sometimes it's the same thing as how if you hold a TV antenna in your hands, you get improved reception, your body is sort of a metal detector circuit.

Sometimes circuit boards just become super sensitive as they are failing, or they got a very mild short circuit.

if two pins on the integrated circuit are corroded or something and just barely short circuiting, something as subtle as your body's energy field can make them alter the circuits in the board, I have witnessed that, and there will always be a point when it's going bad when it's just at the right, most sensitive stage.