hey, my wife and i just recently bought a home that was originally built back in the thirties. it was added onto in the sixties and then more recently (1992) the electrical outlets. all but one or two outlets have a three prong plug. just the other night i put in a three prong plug and there wasn't a ground wire present. is this ok or not. all i have plugged into the outlet is a wirelss device that turns on a 5 bulb over head lamp. the lamp its self has a two prong plug, but the device has three. it seems to work fine. i'm just looking for some advice.