My range hood has touch button controls. Just the slightest touch of a finger changes functions. I never gave any thought to how this works. This morning, I had just finished wiping my hands with a paper towel and had it still wrapped on my hand. I touched the button to turn the exhaust fan on with the finger covered by the paper towel. ..... Nothing..... I pressed a little harder..... still nothing. I took the paper towel off and brushed the button ever so lightly. The fan came on. How does that work? Obviously, it's not pressure that turns it on. But what?