Light switch making popping noise.

July 1, 2009 6:33 AM

Calling all MeFi electricians: why does my light switch make a popping noise, and will it kill me?

I have a light switch in my kitchen that intermittently makes a small popping noise when turned on or off. Usually it'll happen a few times in a row, and then not happen again for several weeks. I have not experienced any flickering/dimming of the light in questions and I have not seen any sparks. There have been a few times when it's happened and I have smelled a little bit of ozone (at least I think it's ozone). I have tried to google this, and it seems like the answers range from "this is going to start a fire, call an electrician immediately" to "the switch is going to stop working eventually, but it's not a safety hazard, so replace it whenever." I don't mind replacing the switch if that is what's needed, but money is tight enough so that I really, REALLY don't want to call an electrician if this is not a big deal.

posted by feathermeat to home & garden (12 answers total)

It's sparking inside the switch, and that's the ozone you're smelling. Or melting plastic. I'd replace it immediately.

While an electrician would be desirable, replacing a light switch is very low on the homeowner repair required skill level. Go to Home Depot -- they have all the equipment, and they have instructional books for sale on the subject, too.
posted by Cool Papa Bell at 6:41 AM on July 1, 2009

Replacing a switch is one of the easiest electrical jobs. You could do this yourself and the only cost would be a few bucks for a switch. You'll find plenty of how-tos around by googling, but you basically just turn the power off at the electrical panel by flipping that particular breaker to the off position, check that the power is off at the switch, replace the switch with a new one, making sure that all the wires are exactly the same as the old switch.
posted by orme at 6:43 AM on July 1, 2009

The danger level is fairly low but, as noted above, it's an easy fix. New switches cost less than a buck, unless it's a 20 amp circuit in which case it's a buck and change.
posted by jon1270 at 6:53 AM on July 1, 2009

HOW TO AVOID INJURY: Turn off the breaker (or, remove the fuse) for the circuit that send power to that light switch. This is a very important thing to do, and a lot of people are careless and skip this step, which means that they're handling live power lines.
posted by Citrus at 7:07 AM on July 1, 2009

Be aware of what type of switch it is before you buy one for replacement, though. It could be a three way or four way switch if you have multiple places you can control the lights. The best thing you can do is get a handful of wire nuts, turn off the breaker, remove the switch, place a wire nut on each wire and take the switch to your hardware store or home center to
match it.
posted by tomierna at 7:09 AM on July 1, 2009

nthing that it is easy. Also since almost everyone has digital cameras it is worthwhile to take pictures of the wiring before your disconnect things.
posted by mmascolino at 7:16 AM on July 1, 2009

...they have instructional books for sale on the subject, too

I'd be willing to bet that they (or Lowes) even have little freebie how-to sheets. As stated, this is a pretty simple repair. Once you know how to replace the switch, replacing an outlet later on is basically the same process, so going forward you'd be able to fix either one. Go for it, I say!
posted by jquinby at 7:17 AM on July 1, 2009

I've seen metal melted from arcing due to a loose connection, even though the metal was designed to carry current. This wasn't in a light switch, but I'd be concerned about the fire hazard in your situation.
posted by D.C. at 7:41 AM on July 1, 2009

No electrician. Turn off the breaker and replace it yourself for a dollar, as others have said.

In fact, turn off the breaker now, note the parts and how they connect (or take a pic) and then just duplicate that with the new switch.

You may even SEE what is touching and sparking (bare wires?) and be able to fix it by re-twisting wire nuts or otherwise moving wires out of the way now, without needing any new parts.
posted by rokusan at 8:13 AM on July 1, 2009

Here are instructions for what you'll probably need to do.


Here's close to a worst-case scenario; replacing a switch from the Eisenhower Administration with unmarked wiring.

Piece of cake.
posted by chazlarson at 10:34 AM on July 1, 2009

Be safe, it's easy.
posted by pointilist at 7:31 PM on July 1, 2009

And, while you're replacing the switch, check to see what type of wire you have coming out of the wall. There are still some houses (in Canada) with aluminium wiring. You have to buy a switch made for that and not for copper. Easy to check as copper is, ah, copper and aluminium is silverish.
posted by x46 at 4:21 AM on July 2, 2009