Break a circuit on a alarm clock

Transistors can be used - but you do need access to an oscilloscope if the switches are arranged in a matrix. The drive to a transistor needs referencing to the emitter and so isn't a "clean" way of linking two points.
So not that it cant be done but I was assuming that madd444 doesn't neccessarily have access to electronic testing equipment.
Opto-FETS allow you to divorce the driving circuit from the device being driven and you dont need any test equipment and can visually determine where to put the connections (same for relay)