Years ago we connected a DirecTV receiver to a telephone cable that was ran for us. At that time DirecTV required when activating receivers to do a phone check on each receiver. When we did the phone check the fire alarm went off. Next thing you know there is three or four giant fire trucks outside with their sirens blaring.

Turns out the guy that installed the smoke detector spliced into the phone line instead of running his own cable.

Stupid is as stupid does.