On Aug 9, 12:36*am, Ivan wrote:
Heard a loud, mysterious whine in the bathroom next to my home office.
Audible in the basement, too, loudest under the bathroom. *One by one,
turned off each of my 32 breakers. The whine disappeared when I tried
the 30th--which made no sense, because it controlled the kitchen, at
the other end of the house; and then it re-started before I even
flicked the breaker back. Finally got smart and checked the outside
valve for the garden hose. *It was turned on, and leaking slightly
around the valvestem, while the hose was shut off by its spring-loaded
nozzle. Turned the valve off and *the whine stopped. *Lesson: Not all
electrical-sounding whines are electrical.

Regarding strange whines...

I started my van last night. As soon as I started it I heard a high
pitched whine and said "Oh Crap...please, not now...I've got a 1000
mile vacation trip in a couple of days."

I shut the van off and was relieved to find that my neighbor, hidden
by the bushes between our driveways, had started his shop vac at the
exact instance I started my van.

Whew!