Smoke Detector hard wired, no battery!
I have an old smoke detector (brk brand) that is hard-wired. There is no battery in it at all, no battery back-up (It never had one, it's a sealed unit). It started sounding very loudly and my son's friend just pulled the white wire out of it so it would stop sounding. We tried to clean the smoke detector using compressed air, and it still won't stop the sound when I reconnect the white wire to the unit. As of now it's hanging from the ceiling with a black wire connected to the unit and the white wire is hanging loose.
I'm not sure what to do now. We could just go buy a battery smoke detector, but what do we do with the wires hanging from the ceiling for the old unit? Or - we could get a hard-wire replacement. Are those easy to install?
Help please if you can, I realize this is hazardous!