If I install a security alarm and activate it before leaving the house, but leave the door unlocked - is that more secure than locking the door with a key, but not activating the alarm?
It's called a capacitor. When you apply power to a smoke detector with either wired or battery power it charges the capacitor. It acts like a battery so that the detector will work for the longest time possible if all else fails. To get the detector to quit chirping just take it down, remove the battery and hold the test button down. It will go off for a second then die off like a horrible haunted little noisy smoke detector without power.
It sounds like dust that settled above the fire alarms. Use a soft brush and clean around them. The dust probably came from the sheetrock work.
they have one at walmart for like 10 bux it comes with a thing that you slide on your seat post
