Just moved in to a new place and I've noticed during the quiet of the night when trying to sleep that there is this periodic electrical sounding buzz, sort of like the hum of my subwoofer if I leave it on with no audio input.
I've timed its frequency, and the sound persists for 1 min 25 seconds every time, and then switches off for about 1 min 15 seconds.
It isn't only at night either; it's just that noises of the day usually drown it out. It seems to persist all day.
Anyone had experience with something like this and could help me identify the source? I can't quite locate the exact source of it, but it sounds like it may be coming from the place above me.