How easily does this need to be reset? Meaning, are you going to hit it once then have time to reset or replace a switch like RavensCraft suggested or do you need to hit it again and have it come back on?If it's a one shot then reset thing then you can use a strip of tinfoil as a wire. Place the tinfoil in such a way that when you hit everything it breaks, cutting the circuit. You then reset the circuit by replacing the tinfoil.If you need to be able to turn it on and off then use a normal push switch. Just set the switch back from the surface you are hitting so that it is contacted only enough to barely toggle the switch.