We have two smoke alarms - the type that are wired into your electrics. For the last two nights, one has been beeping quite a bit. It started intermittently and is now every three minutes or so. I know if it was battery operated this would mean the battery needed to be changed, but since it works off the electricity, does this mean that its just broken or there's a short?? It's very annoying so we're going to have to take it down/switch it off if we can't figure out what the prob is. Anyone any ideas?