if that ground is raw copper that is a 115V 2 wired socket with a black and white.......black,red and white are 220V black is 115v to ground and so is red between red and black are 220V do you read 220V:huh: on the exsisting socket
Unless this is type SE cable it is wrong and should be corrected. A bare ground in NM cable should not ever carry neutral current.I have a 50 amp breaker feeding a 3wire 220V (black, white and ground) receptacle.