Electricians - Buzzing outlets

We got this house last summer, and there’s an outlet in the foyer that will buzz occasionally. It seems to be triggered by increased heat or humidity. It will often buzz when I’m cooking.

It’s a 79-year-old American Foursquare. Upon further sleuthing, the outlet looks like it’s connected to another sort of electrical do-dad on the other side of the wall, which is near the steps leading into the basement.

I wondered if it’s attached to an archaic smoke alarm or something, but it buzzes and then sort of sputters and stops…then starts again. If I fan a nearby door back and forth, it will stop.

I have some guys in the kitchen (adjacent to the foyer) putting in a countertop and something they’re doing is causing it to go off…at least I think…it might be their saw or drill kicking up sawdust, or maybe the open front door is letting warm air in.

I obviously have no clue. Anyone ever seen/heard/experienced this? If so, could you offer a remedy?

The outlet buzzes?
How loud is it? If it’s loud, then there is probably some unknown device in there.
If it’s quiet, then there might be an arcing problem, which would be bad.
Is it possible that the transformer for your doorbell is attached to the back of this outlet, on the other side of the wall?

If the outlet itself is buzzing & vibrating, that’s definitely dangerous.

Check to see if anything is loose. Take something non-conductive (like a wooden or plastic spoon) and try pushing lightly on the outlet. Does it move around in the box? Does the whole box seem to move in the wall? Do the wires touch the box and spark when you move it sideways?

Anything like this indicates a problem, but one that’s easy to fix: just turn the power off, take the cover off, tighten all the screws up, and put it all back together.

That other do-dad that’s connected to it may be a doorbell transformer or thermostat transformer that is buzzing. A little buzzing may be normal. Much buzzing is not normal and may mean that the transformer is either loose or going south.

Does the do-dad look like this?

If it ain’t that try to give a better description of this do-dad.

The other thing that could cause the buzzing would be a loose feed-through wired outlet. IOW, the contacts that the wires are connected to in/on the outlet are loose and the buzzing you hear is actually a continuous controlled arcing condition which ain’t good either. Have it checked out asap.

You know, I missed the doo-dad part of your post the first time.
It’s almost certainly the doorbell transformer.
Ignore it, or get a new one, if the buzzing is annoying you.

Buzzing often means that it’s arcing, which is one step away from a house fire. I’ve had to replace four outlets that buzzed, three of them being scorched. I have aluminum wiring in the house (which I would love to use to string up the guy who thought that was a good idea), and the wires loosen and start to arc against the outlet posts. Replace the receptacle ASAP, and make sure you use the correctly rated receptacle for the wires that connect to it.

Vlad/Igor

Either it’s arching or a transformer is attached and the transformer laminates have separated allowing the noise you hear to occur. Replacing the transformer is the only option to stop the transformer noise. If arcing is occurring in the socket, you need to replace the socket, and not just tighten up the screws.

If the wiring is aluminum, I strongly urge you to contact an electrician to handle this properly. There are “pigtails” available that let you use regular wiring devices with aluminum wire, but they are not a do-it-yourself item. There’s nothing inherently wrong with aluminum. The problems come from the material not being used properly.

That said, I highly doubt an 80 year old house will have aluminum wire unless someone did some renovations in the 60’s or 70’s. It is possible that the wire will look like aluminum - it wasn’t uncommon for wire in the first half or so of the century to be tinned - it will look silvery, but if you scrape it with a knife or look at a cut end, you’ll see it’s really copper.

First thing to try is to cut the power, pull the outlet out of the wall and tighten the screws. If it’s a “back-stab” outlet, pull the wires out of the stabs. (There are release tabs near where the wires go in.) Look for burnt spots or pitting. If the wires or terminals look burnt, replace the outlet, and clip the burnt ends of the wires off to get at undamaged wire.

Re-connect the wires under the screw terminals, put it all back together and turn on the power. Hopefully, you should now be buzz-free.

Doorbell or furnace transformers can hum a bit, but they normally don’t buzz loudly, unless they’re being overloaded or the internal insulation is breaking down with age and the windings are shorting together. Happily, there aren’t too many kinds of doorbell transformers, and they’re all easy to replace - just take the old one with you to the store to get the right voltage.