I have two hard wired detectors in my home. I have had chirping for two months. First I took the head off and took the battery out. Then I disconnected the black and white wires and recapped the live ends. It still chirps. So then I went and flipped the circuit breaker to the two rooms and the disconnected wiring is chirping still. How is that happening and why? What can I do to stop the blasted chirping?