It is simple to make an electromagnet. However the wiring could not be insulated and it would be necessary to use a heavy-duty magnet to do some damage. It would be highly unlikely that an old electrical building would not use insulated wire.
My point is that the kidnappers would have to fashion their own weapons and couldn't just happen upon them. They would need to supply a power source, probably stronger than the average electromagnet, and make sure that the electicity forms a complete circuit.
Elisabeth
