I wonder, really. I’ve short circuited 9volts batteries before and from memory not much happened. I think a typical average 9v battery can give about .5 amps, so you’d get 4.5 watts, which won’t heat up the metal piece very much.

Since it’s a closed circuit, I also don’t think you’d feel much in the sense of electric shocks.

I’m guessing the person sleeping wouldn’t even notice it