The signal? "Replace smoke alarm battery"

Then it would be periodic but so long between signals that it would be nearly impossible to determine where it was coming from.

gibolt a day ago | parent | next [-]

Maybe it is a musical instrument smoke alarm

	▲	alterom a day ago \| parent [-]
		Wow. I guess they have seen everything now.

hilariously a day ago | parent | prev [-]

What's that beep? Eh, we'll figure it in the next galactic epoch, go back to bed.