Headset - mild electronic shock

If its an AC shock, blame whatever the headphones are plugged into, not the headphones. Faulty power supply or lack of a ground connection to the wall outlet, and/or wall outlet itself not properly grounded. If this is the case, you definitely DO NOT want to ground yourself, or you could get a bad shock. (Granite should be a good insulator, so if you are getting a slight shock sitting on granite,it could be much worse depending on what the voltage is.