Why Does My Electrical Outlet Spark?

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Stephanie Shockley

Subject: My Issue

My wall socket sparks even when there's nothing in it. What should I do? I don't have any money to hire someone to fix it and I don't know how to repair it myself.


Subject: Outlet spark

There was recently an accident where a metal item was place over the prongs of a nightlight and then put into the outlet. The nightlight never was fully inserted and only just touched the outside. There was a small spark and the lights in the room went out. We guessed it was a short circuit and the lights turned back on after fidgeting with the power box. There was a small burn mark left on the outside of the outlet due to the small spark. Is it still safe to use this outlet if we use the bottom holes and not the top ones? (The ones burned.)


Subject: burn mark on outlet

I believe you are correct, that metal item caused a short circuit. If there is no melted area around the burn mark, then it should be just fine. The safest bet would be to replace the outlet and avoid metal items over the prongs of plugs.

Sheyenne Roesler

Subject: Dishwasher

Last night I started the dishwasher. A short time later I noticed a smell of burning coming from the front of the dishwasher along with some smoke. I turned the dishwasher off and opened the door to see if something had fallen on the element, which it was clear. I shut the door back on and started it. When the dishwasher kicked back in I saw a spark coming from the outlet, followed by flames. I shut off the dishwasher and got the plug unplugged. The fridge is also plugged into the same outlet, its cord was not hot at all. What do I need to do now?

Craig Secor

Subject: Please do not have multiple

Please do not have multiple appliances plugged into the same outlet. Did you know that my garbage disposal is on it's own dedicated circuit breaker?

Jean Greenfield

Subject: wires and wiring

While I was sitting at my kitchen table I inadvertently brushed my foot against the cords in the outlet set in the very old outside wall opposite me. Immediately, sparks/spits came from there so I crawled under the table and unplugged my radio & a lamp. Someone had kinked the radio cord and tied the kinks together -most likely very recently.This radio cord is at least 15 yrs old, foreign, and of soft rubbery material. Must I get someone to delve into the circuit and it's attachments or can I just cross my fingers?


Subject: Electric outlet blown out

Question: I work at a fast food reasturant, mc donalds, and One of my tasks is to clean behind the grills. Just today I cleaned was performing this task and the outlet blew out. I am not sure if it was my fault. I am aware that water on the prongs could have been a possible cause, but the in the past the prongs have been a bit damp and this has not happened. I did notice that the socket that blew out was loose. Although these are to factors that could be the cause. Im not sure what caused it exactly. The sockets used for the grill were not topical sockets either, they had about 5 prongs each some 4, and where shaped oddly. If anybody cares to enlighten me on this situation? I would very much appreciate it. Thank you.


Subject: Plug in

My plug in my house are wet by water should i turn off that breaker of that plug and the other switch of the other breaker plug are on is this safe or should i turn it off to?

ashley pool

Subject: electrical outlet sparks

my husband and uncle installed our new air conditioner last year and they didnt put a face plate over the outlet that u plug into the wall and now its sparking when i turn it on


Subject: Outlets

A reason for the cover plate is to prevent children, animals, and other object reaching into the the box where contact can be made. You could be electrocuted or short out the circuit or device that's utilizing the outlet. The other reason is to contain any type of electrical spark or arching. Every time the a/c kicks on it pulls a lot of power. Which also create arching. Could be me numerous things but before putting a cover plate would be a good idea to inspect the outlet for black, soot looking marks.

Ken Jackson

Subject: spark

The most dangerous thing about electricity is usually the advice from a want-to-be electrician who is not sure what end of the cord plugs into the wall outlet. I can't believe that sparky would think its normal to have a wall outlet doing this? I could see if it was the 4th of July, and did it, but not every day? It should never spark. Get a insulated screw driver and tighten ALL connections, including neutral and ground wires on that circuit. KJ.


Subject: Hire a License electrician

I am a electrical engineer / electrician your comments on here are not to clear. I got news for you permalink it is not normal for any outlet to get warm got it. You are another dangerous person giving out advise with some knowledge.If the draw is to high your over current device in the load center will trip or a fire is possible. Loose connections are most seen because people who install them stab in the back of the outlet. the spring tension gives away due to heat . The outlets are cheap garbage.If you have any electrical problems get the proper help. It could save your life.

Prentice Adler

Subject: outlets

Randy is right. I spent 40 years in the trade. First of all ,sparks are never good, they are at temperatures high enough to start fires with any material and should always be avoided. If you are unplugging devices under load (while turned on) , you have a good chance of creating a momentary spark. This only damages the outlet if this practice continues. If an outlet sparks while it is used, stop using it immediately and call an electrician.

David Whiteley

Subject: What causes an electrical outlet to spark

We found some old outlets in our church where part of the circuit was in the cover plate. This had deteriorated over time and gave a spectacular show until replaced. It had previously check out ok with a hand-held test unit. Other receptacles were wired wrong and were replaced when other electrical work was done.

W Jay Hall

Subject: outlets/switches arc

Inductive kick is term sometimees used for spark caused by a collapse of the magnetic fields around the conductors. Similar to old autotransformer used in car ignitions giving "spark" across the spark plug providing 20K plus low current jolt. Similar to static discharge

Gerakd Hintlian

Subject: Electrical shorts

I have generally found that most sparks and shorts are the result of a bad connection in the plug of the device itself. I have found very little problems with the outlet itself. Maybe my experience is rare, don't know.
Gerry Hintlian


Subject: Power plug heating

It's normal for a power plug to get warm if it is supplying current to a high-power appliance like a hair dryer, iron, or vacuum cleaner. Moreover, it's normal for a spark to appear at the outlet if the plug is pulled while the appliance is still on. But the outlet and plug should never become hot, or emit odors or smoke. If that happens, unplug your appliance and replace the wall outlet.

Dave Haney

Subject: too big a fuse

very common problem i run into a lot is too large of fuse for the size of the wire,replacing a fuse with a larger value fuse is asking for trouble.many people theorize that by putting in a larger fuse i stop the fuse from blowing,but in all actuallity they are actually doing more harm than good,a fuse keeps blowing over and over it is telling you something is wrong either with the wiring or the appliance you plugged in.or that circuit is simply overloaded.


Subject: Heating up

When you take out a plug from a wall outlet it should be cold to cool at the pins. If hot it means the connection is poor or and the equipment plugged in is taking to much current. If you hear arcing or sparking and maybe see smell smoke or a fish like smell then the socket on the wall needs replacing. Maybe the plug on the equipment too. This state of affairs applies to all electrical equipment wherever it is.
The cause is a lose connection or poor connection where the electricity is leaving the socket and travelling to the plugged in appliance at the socket/plug junction.
If the current can not flow easily with little resistance, as when the connectors are lose or poor, the resistance will be a lot higher than it should be so heat is developed because the higher resistance causes the voltage to be lower than should be, at that point, so it manifests itself as heat.
This is waste power, in watts, and this causes heating.
Watts is power and is the voltage, say 120 V ac times amperes, say 5A ac which equals 120x5=600 Watts.
The item is rated at 600 Watts, say a small iron for clothes.
Note that 5 amps needs to flow through the iron AND through the wires in that circuit and the socket/plug junction. Normally the wires flowing eventually to that iron pass through the circuit wires that have a very low resistance so they drop (lose) very little voltage and the appliance gets a pretty full 120 volts.
If however there is a lose/poor connection like at our socket/plug junction that will have appreciable resistance. This will oppose the current flow to the appliance. This will lower the applied voltage and so less power will arrive at the appliance. BUT because of this higher than should be resistance which loses some voltage but still has current flowing to the appliance it means that the socket/plub junction is lower the voltage and lessening the normal current.
Where ever you got a voltage drop and a current flow you USE power. So the junction heats up.

Tim Slocum

Subject: Circuit Analyzer for Outlets

Some electricians and Home Inspectors may use a Circuit Analyzer that will identify issues with outlets. These devices will identify abnormal voltage drops at each outlet to alert you of potential hidden problems. Large voltage drops at an outlet along with a power hungry device plugged in are all you need for a fire.

As a Home Inspector I use this on every home inspection for the safety of my clients.

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This can be maddening. Over the past 40+ years, in 4 houses, I have had or have run across this problem from gas meter leakage, water well pump column vibration, doorbell transformer, circulating pump, an extremely small (mist spray) water pipe leak, flourescent and sodium lights, security system horn dead battery, gas meter leaking slightly, bees in wall, bat colony, electric typewriter left on, stereo left on very low, and speaker inductive hum.

This seems to be a popular and recurrent question, so I am going to give the long answer for use by future questioners too.

I am assuming you do not hear this noise away from your house, or that other family members can hear it to. Obviously, if you hear it elsewhere also and other family members cannot hear it, then maybe you have tinninitus or are hearing your own high blood pressure blood flow (seriously). This commonly gets more acute at night when it is quiet, so all you are hearing is your internal ear sounds. I had this happen once because of a middle ear blockage - drove me crazy, getting up in the middle of the night because I thought I heard a water leak through the walls. Try putting on a pair of earmuffs or hearing protectors - if you still hear it or hear it louder, this is probably the case.

One method if hum is on the clearly audible side is make a 2 foot long cone out of paper to hold against your ear - like an antique hearing horn - then in each room face each of 4 directions while listening for where sound is the loudest, and turn your head to pinpoint the exact direction - I would spend 10 minutes doing this before getting into detailed stethoscope listening.

Otherwise, sounds like time for the old stethoscope (about $12 at a drug store - get a metal soundhead one, not cheap plastic, which does not pick up vibration as well). Also, if you are older (say over 35 or so) your hearing might have started to deteriorated with age, so if you have children or grandchildren with sharp hearing, they might be able to help track it down. I am sure a young child or grandchild, if you have one, would love this sort of treasure hunt (with appropriate "treasure" for a reward for tracking it down). 

Being careful not to come in contact with electricity with the stethoscope, check all the likely sources listed below. Start by placing it against pipes and walls and floor in each room of the house - water sourced noise goes a long ways, and tends to reverberate in the walls, so if that is the source likely to hear pretty easy. Hold stethoscope against bare pipes, both hot and cold, and heating system radiators or hot air vents.

If listening to water and hot water heating pipes indicates it is not water sourced, then you could turn off the master (outside) breaker or all the inside breakers and see if it goes away. I would only do this during above-freezing weather and early on a weekday, just in case a breaker fails to turn back on correctly when you switch it. Older master breakers particularly, which typically have never been used, sometimes break or fail to reclose properly after being shut off, so then have to be replaced. You want to be doing this at a time of day when, if necessary, you could get an electrician in the same day to replace it without paying weekend or nighttime emergency call rates.

If turning off the master breaker (or all other breakers) eliminates the hum, then turn them on one at a time until you find the one that turns the hum back on, then track where that circuit likely feeds (hopefully it is labelled) and check every switch, outlet, and light fixture.

Humming sources include (not in any particular order, a + in front means likely or common source of humming, - means rare or not likely):

1) + toilet fill valve - slightly leaking toilet inlet valve (listen where water tubing comes into toilet tank, and look inside tank to see if there is any water flow into or ripppling of the water in the tank or the bowl, or from the bowl filling tube (usually a small black plastic flexible tube which comes out of the fill valve (usually far left side of tank) and is clipped onto and discharges down into a hollow vertical brass or plastic tube or pipe in the toilet tank, which refills the toilet bowl after you flush)

2) + leaking faucet - kitchen, tub, shower, sink, utility tub, etc - it is amazing how just the smallest valve leak can make a hum or hiss that you can hear through the walls (especially at night), but only drips every few seconds.

3) - electric service meter dial motor

4) - electric breaker panel - rarely, a loose main power feed to a panel (especially with aluminum main service wire) will get loose enough that it vibrates back and forth and hums in its connector. A loose bus or snap-in breaker slot cover plate in the panel can also do this rarely

5) - gas meter or overpressure vent (unlikely, as you have had it replaced)

6) + boiling in the bottom of hot water heater or boiler because of buildup of lime, but would usually be intermittent - only when unit is heating

7) + furnace fan or electrostatic filter (forced air heat), or circulating pump (hot water baseboard heating), or steam condensate pump or overpressure venting (steam system).

8) - gas control valve or electric control box on a gas furnace, or its transformer (most have a 120V to 24, 16 or 12V transformer inside the front of the furnace

9) + air filter or electrostatic filter alarm on forced air furnace - some have a passive "whistle" opening that sounds softly when the filter is getting blocked, and if blocked with dust could make a hum rather than a whistle.

10) + Some water softener systems also have an "alarm" device to tell you it is time to service the unit, so check that if you have such a unit.

11) - a slightly leaking overpressure/overtemp valve on hot water heater or furnace (would be dripping)

12) - air venting from the air vents on hot water heating system. These will commonly make a hum or wheeze sound, for only for a few seconds at a time - not continuous unless leaking water

13) - city water system booster pump sound through the water column (if there is one near your home) - listen at the incoming water pipe - if much louder there than at other pipes within the house, that could be a house, though unlikely. If you think this could be it, find your water shutoff valve (typically 10' into your lawn from the street) and listen there. Would also be audible at neighbor's service pipe if that is the source.

14) - gas system compressor sound coming through gas pipe - listen to gas pipe outside the house and inside the house near furnace - if louder outside,, this could be a possible source, but the compressor or pressure reducer would have to be near your house. Would also be audible at neighbor's service pipe if that is the source.

15) + auxiliary booster circulating pump in your hot water or steam heating system (there may be one separate from the furnace, likely in the basement or a utility closet - most commonly found on  multi-unit apartment building with central heating and in 3 story or higher buildings, but you never know)

16) + a water leak, either inside or a leaking hose bib or pipe, or in your service pipe coming to the house

17) - electric on-demand water heater or electric-powered water filtration unit under the kitchen sink or inthe basement

18) + refrigerator compressor or fan hum

19) + doorbell transformer (front or back door - transformer is usually NOT at the doorbell, it is usually mounted in an open space like nailed to a basement joist, in an entry closet, or in the cubby space under the stairs - always physically near to the door, but NOT always on the same floor)

20) - any instant-on device like a TV

21) + any audio device (stereo, iPod, music player dock, computer, etc) that may have been left on at very low volume. Also, VERY rarely, if stereo or external speaker wires are run close to and parallel with an electric wire in the wall, they will acquire an  inductive voltage and hum.

22) + anything with a transformer, including stereo, add-on computer or iPod speakers, battery charger (rechargeable batteries or spare car battery or rider mower or boat battery charger), any portable electriconic device. Also portable device chargers (computer, iPod, cell phone, etc) - even if the device is not plugged into the transformer, as long as the transformer (charger) if plugged into an outlet, it is transforming high to low voltage, and transformers commonly hum

23) - electric typewriter left running

24) - electric ultrasonic cleaner or denture cleaner or electric toothbrush left on 

25) - home hair drying hood left on

26) - a lint buildup-jammed bathroom, kitchen, or attic fan. Many of these have, for safety, so called "self limiting" motors that if they jam just sit there and hum, but do not burn out.

27) - an attic cooling fan whose thermostat has failed, so is on all the time

28) - electronic furnace thermostat

29) + air conditioning unit, or aquxiliary air conditioner evaporator

30) + humidifier / dehumidifier - either permanently installed or portable

31) + portable heater / fan / air purifier

32) - automatic animal feeder waterer - either water supply or electric, as applicable

33) - dishwasher motor runningcontinuously - not shutting down after end of cycle

34) - convective or direct-vent oven or cooktop exhaust fan not shutting off

35) + flourescent (tube or CFL) or sodium or halogen light bulb / ballast hum (either inside, outside front door fixtures, or public street lights). These can hum quite pesistently when the starter circuit sticks on, or the bulb is dying and will not start (light completely), so the started circuit tries continually to start the lamp - can make a hum audible up to a block away on street lights.

36) - a dying electronic photocell designed to turn on your outside lights

37) - home security system, especially its alarm or horn. If the alarm is sounding but for some reason the main power is not getting to it, then as the battery goes dead (or if full voltage is not getting to it) is can give off a squeek, hum, or rasping sound - ditto if insects like wasps or hornets build a nest in it, so it cannot sound correctly.

38) + well pump, pressure tank, or filtration system, if you are on a well

39) + insect or bat nest in the attic or walls or in outside bins or cupboards, electric panel/meter, or outside telephone connection box (bees /wasps / hornets most likely) - though this usually varies by time of day, although it would "pulse" at the time of day when they are waking up or going to sleep.

40) + carpenter ants or termites - their continuous chewing of the wood can sound like a hum till you get right up against the colony, then you can actually hear the chewing

41) - a regional hum, as has been occurring at times in Ohio, Wisconsin, and Arkansas - where micro-seismic activity causes a hum or booming sound. Google or call your local paper and see if anyone has been reporting this in your area.

42) + outdoor power service transformer - either a metal (typically army green or gray) about 1 foot diameter "can" mounted on a power pole if you have overhead service, or a 2-3 foot cubic metal box on the ground or in a manhole pit near the street if you have underground service, which usually serves 4-6 houses (so may be in a neighbor's yard) and will have a voltage rating marked on it, usually in yellow stick-on lettering - like 4160V - 220V. Usually has high voltage - keep away safety markings on it.

43) - you have found where the Caddyshack gopher (who hummed to himself) moved to after Bill Murray blew up his happy home at the golf course.

Hope this list helps you (and future users with the same question).

Unless you feel uncomfortable doing minor repairs or don't understand that you should turn the electicity OFF before doing such installations...you can do the job yourself with a screwdriver and needle nose pliars...within 15 minutes. 5-10 minutes if you've done it before.

The amperage is the rated power it can handle. Modern houses are generally built with 200 amp panels, and a lot of the newer ones are going 300-350 amps as more and more electronic devices and fancy and high-demand kitchen devices and increased lighting are used in homes.

Both are just as safe - the 200 amp one will just have many more breaker slots, allowing way more circuits, and providing more room for expansion in the future, especially for power-hungry things like shop tools. Each uses only as much electricity as is used in the circuits - the panel itself does not consume any electricity, so no long-term impact there. It is just a circuit connection box where the individual circuits are connected, with circuit protectors (breakers) in line before it connects to the main line to your electric usage meter.

Unless you are real tight on money on this job, I would upgrade to 200 amps capacity - the incremental cost is about $100-200 or so over the 100 amp panel. If your incoming power line cannot handle 200 amps, you could install a 100 amp main breaker to keep the power company happy but put in the 200 amp breaker panel, so in the future a main line upgrade could be done with only a main disconnect breaker upgrade of $100 or so, without having to change anything inside the house.

Having the larger panel, especially if 200 amp capacity all the way from the meter, can be a selling point (or rather, lack of a negative point) to a potential buyer with lots of electronics or who is into shop power tools. It would also facilitate conversion to electric heat / water heating if someone wanted to do that.


As I understand it, you are looking at putting in a fan where there is no ceiling electric outlet. Since I am not sure, will try to break out piece by piece, undersanding these wouyld all be lumped into one job (possibly excluding wiring new outlet and switch). I hate to be so general, but access is the key here - if access is easy and there is a suitable light switch in the same room, cost can be at the low end of this range. If assess is poor and you don't want holes knocked in your drywall, then get more expensive real fast.

1) cost of fan typically $125-250 unless high end model

2) remove existing regular 4" box, install supports to joists and new box (ceiling fans need specially supported boxes due to the extra weight and swaying motion of the fans) $50-75

3) tap electric from existing circuit at existing box, upgrade existing light switch box to add one or two more switches (Adjustable for fan speed, 2nd for light, if so equipped), run wiring to ceiling fixture $125-250

4) put up fan, connect, test $75-100

So - total About $250-425 with no box there now, plus cost of fixture. A simple install to replace an existing fan, or install where the ceiling box was wired for a fan, would be only about $75-100.

This all assumes the existing nearby electric circuit can handle the addition of the fan - if not, then wiring cost will go up. It also assumes there is access via open attic or joists to install the wiring. Otherwise, installation cost OK but does NOT include repair to holes in drywall or ceiling to pull wiring.

Note also that an existing ceiling light box would probably NOT fill the bill - code in almost all jurisdictions requires 12 ga wire for fan motors, most household circuits are 14 or 16 gauge, so would need new wire pulled from a circuit with adequate capacity.

Get bids ! I worked on one job where the owner in a high-end house decided to put in fans with fancy candeliers underneath after construction was done - cost almost $3000 to do installation because all the wall and ceilings were finished in a high-end finish, so all wire pulling had to be done remotely - including removing siding to put in pull boxes at changes of direction and fasten conduit to studs. PLAN AHEAD !