Grounding is an important electrical safety feature on receptacles, sometimes called outlets. It is important in this day and age to have a ground on the receptacles in your home. You likely have one of two types of receptacle, a polarized or a three-slot receptacle. In order to perform this test, you'll need some type of electrical tester. This could be a neon tester, a receptacle tester, a voltage tester, a receptacle tester, or a multi-meter. Let's take a look at the testing procedures for both polarized and three-slot receptacles.