Any fluorescent light fixtures in the area? Another possibility is a doorbell transformer. Nothing that hums should be buried in the wall.

There are no light fixtures on that wall. But there is a bathroom on the other side of the wall and it has a light fixture on it. It is a small sconce with a small curly-Q type energy saving light bulb in it. I've been using those bulbs for over a year. (The house is about 50yrs old.) Don't know if the age or anything would matter.

Could very well be that lamp (light bulb). Try a regular lamp and see if it goes away.

I took the light bulb out---the humming is still there.

I would like to "thank" the members who responded. I still have the humming noise, but I really do appreciate the questions/suggestions.

If anyone can think of anything else that might help, that would be really great.

Again, "Thank you" for your response.
cad1destiny

Another possibility - if the bathroom is on the same breaker as the bedroom (the one that stops the hum when off), could there be a medicine cabinet with an unused fluorescent light ? The ballast in the fixtures will sometimes hum, I have not seen one hum without a bulb in it, but if there is a burned out bulb it is trying to light, that could be the cause of the noise.

I would trace everything that is on that circuit, and unplug everything one by one to see what stops the hum. Keep us updated

Is there a "razor only" receptacle on this circuit? These receptacles contain a transformer and over time, they get loose and hum really bad.

To: w0lley32

What is a "razor only" receptacle? You asked about that in your post---I have no idea what that is, can you explain or describe in a little more detail.

Thanks,

Before GFCI's were affordable and reliable, the only receptacle you could have in a bathroom was an ungrounded receptacle mounted in a 2-gang box covered by a roughly 4"x4" plate engraved "razor only". That receptacle was on the secondary side of a small isolation transformer, barely large enough to power an electric razor (I think they were rated at something like 15 or 20 VA). I don't know if they were also used in the US, but here in Canada they were in use up to at least 1984.

I've also seen some old vanity lights that had them built-in. They had a small two-prong receptacle on the side of the canopy into which you could plug a razor. How old is the small sconce you mentioned? Does it have a receptacle? If so, try turning off the breaker, removing that sconce and turning breaker on again.

w0lley32,

I tried what you suggested, there are 2 sconces, so I
removed them both. I did one at a time, and checked for the "humming" after each one.

The humming is still there, but thank you for the suggestion.

On another note, when I put the lights back together---one is working fine. But the other is not working. On the one that is not working. When I took the wires apart--it appeared that the black wires/casing had a small area that had melted togehter. Would that make it not work?

I took light fixture off wall and when I replaced it--it will not turn on.

When I took it down, I made sure that I looked at how the wires were connected. There was 2 white ones together, 3 black ones together and then there was one green one with a cooper one. I put them back together the same way--but now the light won't come on. Any suggestions?

Also, could it be dangerous?

GFCI on the bathroom wall?

Hmm. Melted is never good. If you are absolutely sure you put the wires back together correctly, then it's time to call an electrician. Sounds like something is loose or overloaded. Is it all copper wire? What's the outer casing? A green or orange fabric-like outer sheath?

Could it be dangerous? Absolutely. You never mentioned if there's an outlet/socket in there.

A shaver-only outlet will hum, it's an isolating transformer (delivers 120/aka 110 volts but is physically isolated from the house wiring, limiting the size of shock you can get) - they can usually be changed to a GFCI - no more hum. Bulb holders can develop resistance over time which can lead to overheating and humming, also, those cfl bulbs can too. LED bulbs will be a better option.

If in doubt, call an electrician.

I get a humming like that in an outside wall, but it's the neighbours' ac unit and sometimes hot tub, it's something to do with low frequencies!