I had the same problem in a house when I moved in. I kept hearing this annoying beep every few seconds. It was the next door neighbours alarm. Luckily it stopped after a few weeks. I could have gone round there an ripped it off the wall anyway though, because he was a weird guy. Once I caught him climbing on my roof looking through the window at me cooking. :O_O: An another time me an my brother were doing impressions of people an laughing, when he came next to the wall, an growled!