For the last 24 hours, there's been a constant high pitched sound coming from within my first floor bathroom wall. I've tried a few things and can't figure it out.
- We moved into our townhouse 2.5 years ago. It was built in 2001 and we have two neighbors that we share a wall with on either side of the house.
- Everyone in the house hears the high pitched sound.
- I located it on the first floor bathroom wall slightly lower than the electric outlet and light switch. This wall is not shared with either neighbor.
- I've turned off all electric breakers. Sound persists.
- I've turned off all water to the house and drained the pressure in the bathroom sink. Sound persists.
- Checked carbon monoxide alarm and water level alarm in the HVAC and water heater closet. Sound is not coming from either alarm.
- Checked at a couple hour intervals throughout the day and night for any signs of water but there isn't any sign.
- Called a handyman and he checked it out. He thought of two possibilities: insects or drain panel alarm. As we only have one thermostat, he said we shouldn't have a drain panel so ruled it out. Our area is a bit swampy so we do have a problem with spider or camel crickets entering our house.
- The handyman is coming over again today to see if he can see anything with a camera snake, apply some biodegradable pesticide, and patch a large hole behind our bathroom sink. The biodegradable pesticide should only affect insects and if it were insects, they would leave within an hour.
I personally don't believe it's insects because it's been a constant pitch for around 24 hours now but I'm completely stumped so we're willing to try it first. Any and all advice is welcome. Thanks!
Edit: Added recording: https://on.soundcloud.com/qrFNB