@retr0id I'm confused. I expected that you wanted to power something in the part of the key that moves. But you don't need any powered part of the switch there: if nothing else, you can have a reed switch/Hall sensor under it and a magnet inside.
@retr0id Aah, you want to power the keys from a nontrivial distance?
@retr0id Then how does this differ from having a bunch of reed switches underneath that detect the status of the keys? (I'm probably missing some obvious part of the description.)