A lot of the power outlets around your house probably have three holes for a three prong outlet, but is it really safe to use a two prong plug in that outlet?

A lot of older homes still have old-school two-prong outlets. It's a good idea to upgrade them—and you can do it yourself.

In the United States, the majority of three-prong, grounding-type receptacles (as opposed to non-grounding ones with two slots) are oriented with the circular opening on the bottom.

A standard 3-prong outlet is the most common and cheapest type of electrical receptacle you can buy. It rarely costs more than a dollar or two, though some colors cost extra.

Hold off on getting them online unless you buy in bulk. While standard receptacles typically use three wires -- hot, neutral and ground -- you'll occasionally find 2-prong outlets in older homes.

Plugging in an electronic device that has three prongs into a two-prong outlet (like with an adapter) could present a serious ...