There are four main types of electrical switches. They are: single pole, double pole, 3-way, and 4-way. A single pole switch turns an item on and off from that one switch. A double pole switch can turn two different items on and off from one location. A 3-way switch works in a set with another switch and allows you to turn something on or off with both of the two switches. A 4-way switch is almost the same, but allows you to add a third switch location in to turn on or off that same item.