foot switch for live mics?

Dumb questions are allowed in the beginner's forum, right?

Anybody seen, used or built something like this? Or am I barking up the wrong tree?

 

I remember seeing an ad for infrared sensors to turn on your mics. When you walk up to the mic stand, it senses your body heat and turns on. Maybe you want it to be more selective than that. I guess the only other alternative is to wire up some guitar pedal type switches that don't pop into a box with a couple XLR jacks.