PeterH:
TomSlater:
What sensor devices can I use that will only report the proximity of this fake metal detector?I suppose you could install a magnet and use some sort of magnet field sensor to detect it. Alternatively - I know it's a wild thought - why not bury something metal under the floor and just use a real metal detector?
No need to bury anything. I bet there are plenty of pipes, cables and nails he can 'detect'.