Capacitive on switch

While that seems like a cool idea, bear in mind that the switch doesn't just turn the PC on. It also turns it off. I think it would be annoying to have an off switch which is triggered by touch. And I'm not sure how the long-press to force a computer to turn off when it's frozen would work with a momentary switch.
 
The momentary switch should be able to do the off switch function, but my main concern is the voltage, ive already bought one and broke it by teating it at 12v, what us the voltage that runs through the on switch pins?