I hope to God you have a third wire, the ground, running to the back house and all the outlets. If not, you still have a shock hazard. If not, you can ground an outlet by connecting a ground wire to the ground lug and run it out of the house and connect it to a 6ft copper grounding rod driven into the ground or a metal water pipe. NEVER a natural/LP gas pipe. Remember, any appliance that does not have the 3rd ground pin on it, takes is ground from the neutral side of the outlet. The 3rd ground pin makes up if the hot and neutral are backwards. Without the 3rd ground wire connected to the outlet, the ground pin is useless and if the outlet is not polarized, you could plug in the appliance backwards and have a risk.