There are 15 standardized types of domestic electrical outlet plugs in use worldwide. The standard North American outlet, for example, has two vertical slots and a round hole beneath them for ...

While standard receptacles typically use three wires -- hot, neutral and ground -- you'll occasionally find 2-prong outlets in older homes. Since this type of outlet lacks a ground connection, the ...

Not all outlet holes are the same, and there's a reason for that. The shapes (vertical slots, round holes, T-slots, etc.) correspond to specific electrical functions and safety features. Take the ...