Electrical Circuits Without Ground Wires
Many wiring systems installed in the 1950s and earlier used non-metallic wiring, which lacked a ground wire. The ground wire provides a path for electricity to travel along which allows it to flow to the ground rather than anywhere else. Homes from this era have only two-pronged outlets, unsuitable for many modern conveniences.
If you have a home built during this era, the first thing you should do is check your outlets. Even if you have three-pronged outlets they should be checked to be sure a ground wire is actually present. If you find your home is without ground wires you should take action to remedy this situation. Fixing this will first of all protect you from shock. When there is no ground wire present and a problem occurs in a piece of equipment you have plugged in, the equipment will likely become energized and therefore shock you when you touch the equipment.
There are two solutions if your home does not have ground wires and you want to protect you and your equipment. The first option is to run a ground wire to the outlet that your equipment is plugged into. This is espcially important for things such as computers, TVs, ect. The second option is to add GFCI protection. You can do this by installing a GFCI breaker in the electrical panel or by installing GFCI outlets. Simply replacing two-pronged outlets with three-pronged outlets is a violation of the National Electric Code if there is no ground path present.