I had a battery powered one that randomly triggered in the small hours. I'm very sensitive to loud high-pitched sounds, so I woke up with a fright that must have aged me 20 years. Tore that thing off the ceiling, nearly pulling a chunk out with it. Landlord was very unhappy with me doing that, but it was right over my bed.
If I'd had a baseball bat or wooden sword, I'd have smashed that thing free like a piñata!