I have an ungrounded electrical receptacle in my bathroom. The house was built in 1937 and at some point someone rewired the bathroom to install a ceiling fan. The fan switch is attached to this receptacle. When they rewired, they used wire that only had a positive and a negative, no ground. I'm now trying to sell my home and the inspector wants the receptacle grounded. Is there any easy way I can do this? I don't really want to rip up the walls for the new tenant, and the way the junction boxes are arranged in the house, it's impossible to add new wires from the attic or basement. Any suggestions?