Beeping smoke alarm

My smoke alarm has been beeping every few minutes for a week, keeping me
awake when I try to fall asleep. It actually took me about 5 days to
figure out where the beeping sound is coming from. At 2 in the morning
it has driven me so nuts that I grab a step stool to pull down the smoke
alarm and rip the battery out. Sure I'll place it back up on the
ceiling, eventually. Post later.