Triboluminescence is the emmission of light from something when it's scratched, rubbed, crushed etc. Obviously the thing or substance in question has to be Triboluminescent for this to work.
I've carelessly misplaced my magic lamp and therefore can't demonstrate, but here's a picture of a light house. That emits light when someone presses the on switch.
Ten points if you can name it. Seven for the designer.