If you do want to give it a go, connect to the screw that holds the plate
on, don't just stuff a wire in the hole, as it can find it's way to the hot
side.

Good idea re the screw, if the outlet box is metal and if metal conduit is used
to house the wiring. Whatever is done, if it works, when giving it a try, then
get a cheap plug from Ace. Remove the ground pin and use it as a connector on
the jumper wire from the radio.

73,
Bill, K5BY