Any electricians in the audience? Is my house about to burn down? Am I overreacting? Do I have a ghost?

In My Humble Opinion
1

Yesterday as I was getting ready to go to bed I noticed this strange sound coming from… well, I couldn’t tell exactly where. The sound was a hum, the best I can describe it is it sounded like an old-school fluorescent light fixture when the light is turned on. I had never noticed the sound before.

As this was driving me nuts and I couldn’t identify it, I started turning off every electric motor I could think of: the ceiling fans, bathroom exhaust fans, the fridge, the freezer, and the sump pump (unplugged them all). I made sure the heat pump was turned off. I turned off the power to the stove and oven. No dice. The sound continued.

My son and I wandered around the house until we figured out more-or-less where it was coming from: somewhere very close to the front door. So I started flipping breakers and soon discovered that when I turned off a certain breaker, the sound quit. Turning the breaker back on, the sound resumed. This is a 15A 120v circuit that feeds the front porch light, the front entryway light, the hallway light (the hallway is right off the front entry), the outlet in the hallway, the kitchen overhead lights (adjacent to the front entry) and the two bathrooms which are also adjacent to the front entry. The only mechanical things that are on this circuit that I can determine are the two ancient bathroom exhaust fans and both were turned off. The kitchen wall plugs are on their own circuit, and besides nothing was turned on. Indeed, everything was turned off – no lights, fans, nothing plugged into the bathroom or hallway outlet.

The trouble is that this doesn’t sound mechanical. It sounds electrical, as I noted almost like an old fluorescent tube. It doesn’t appear to be coming from something specific like a light switch or a light fixture but rather behind the wall or ceiling. I can’t pinpoint a specific spot but rather a general area. Flipping switches and turning lights on and off made no difference whatsoever. This morning, the sound remains. Turning off the breaker is the only way to make the sound stop.

It doesn’t sound like arcing or crackling, it more of a faint steady humming sound.

I’ll call an electrician in as soon as I can, but in the meantime, what could this possibly be?

A few further details that may or may not be important:

  • The house is a small (~1400 ft²) single-story ranch built in 1967.

  • The electrical system has never been updated so the ground wires aren’t used (I don’t know the terminology). That is, much of the romex used in the house doesn’t have the bare copper ground wire. The plugs are all modern 3-prong plugs, but the ground is just for show.

  • I replaced the front porch light fixture several months ago. I’m not particularly handy but this is something I’m confident I didn’t screw up. Besides, the front porch light wasn’t turned on while we were investigating the sound.

  • The previous owner died in the house, collapsing on the floor after suffering a heart attack while cooking supper. His wife, who was in a wheelchair and pretty much paralyzed and thus had no way to call for help, had to sit with his body for two days before a friend happened by and discovered the grisly spectacle. So maybe it is a ghost – a ghost being fed by the #25 15A circuit.

2

I’d start by leaving the circuit energized and the light switches on, and then take the light bulbs out. It could be an old CFL or LED dying (

3

Sounds like a hidden doorbell transformer to me.

4

That was my other guess, especially since it’s near the front door.
OP, check your basement, in the general area of the front door (and/or under the doorbell chime) and look for a transformer that appears haphazardly screwed to the outside of a junction box.

5

My guess also before I scrolled down.

6

Just to overexplain, that fluorescent tube humming was the ballast which is a transformer. So the guesses of the doorbell transformer are excellent.

7

Intriguing idea. We do have a doorbell. Hmm…

No basment. Our water table is so high I have to have a sump pump in the crawlspace.

The chime is a box on the hallway wall. Taking off the cover, I see this:

[Album] imgur.com

There is no obvious transformer anywhere else. It may be in the attic, which is a tiny crawlspace I can’t fit into :frowning:

Edit: is there any way to cut the power to just the doorbell? Anything that I can disconnect and thus isolate that doorbell transformer, wherever it is, from the rest of the circuit?

8

Another one who thought “doorbell” issue right away.

Does the doorbell still work with the breaker off? If it doesn’t we can rule this idea out.

9

It’s where that black wire is going.

10

Zoom in on the picture and the black wire in the middle runs to the transformer. That might not help much.

11

The transformer is going to be elsewhere. You could try removing one of those terminals, but it probably won’t change anything as the transformer will still be live.

If you remove one of the wires and the noise stops, the problem would probably be with the doorbell button on the outside of your house. Without that depressed, there shouldn’t be any electricity flowing through the chime.

Also, if the other side of that wall is a closet or something, make sure there isn’t transformer in there somewhere.

12

But if I disconnect that wire, the transformer doesn’t have juice, right? And doing so would help determine if it’s the mystery transformer?

No. I just tested it, with the breaker turned off the doorbell does not work.

13

No, because you’re disconnecting the secondary (low voltage) side. The primary (mains) side will still be fully energized.

And the noise is gone, right?

14

Ok, that makes sense.

Yes, with the breaker turned off the noise stops.

There is a coat closet in the front entryway but there is no tranformer in it, plus the sound dimishes significantly when I stick my head in the closet. The kitchen is also next to the front entryway and I just looked inside all the cabinets that butt up to the entryway wall, no dice.

15

So if this is the doorbell transformer causing my mystery noise, which seems to be the consensus, how worried should I be? Can I ignore it or do I need to find someone to crawl into the attic, locate this damn thing, and replace it?

16

Chance of failure is far more likely than chance of fire. Also transformers can hum for years with nothing worse happening.

I’ll take a picture of my doorbell transformer and post it soon.

17

I wouldn’t worry about it beyond it being annoying.

Depending on how handy you feel like being, you could open up any of the outlets/lights/switches that the circuit controls and see if any of them appear to have an extra wire that may head up to an attic and power the transformer. It’ll be tough to do without really understanding what you’re looking for or at, but if you could find it, you could disconnect it. You wouldn’t have a doorbell anymore, but you also wouldn’t have the buzzing noise either.

18

“Is my house about to burn down? Do I have a ghost?”

Interesting combination. Is there such a thing in folklore as evil spirits that cause fires to break out? A Feuergeist?

19

I’ll do that later today after everyone is awake. An extra wire should be pretty obvious. We have a big brass knocker on the door so losing the doorbell wouldn’t bother me in the least.

20

Might help in knowing what you’re looking for. This is what they looked like for a very long time and were usually mounted roughly like this in attics or basements. {click to enlarge}