Then in that case, don't take this the wrong way, do you have battery operated smoke detectors?
Many, many times I've heard the same story to arrive at the house concerned to walk in the door, start to 'play' with the alarm to then find nothing, hear the noise myself and straight away point at the offending smoke detector.
The bill arriving through the letterbox a few days later is not appreciated, especially if this happened on a Bank Holiday.
Please post back and let me know
acorn
May 2008