Does a Three Way Switch Have to Be Grounded?

A three-way switch has four different screw terminals on its body: ... Grounding screws on switches were not always required, so if you are replacing an old three-way switch, you may find one without the grounding screw. The two lighter, brass-colored screws are called the traveler screws.

Do 3-Way switches need a ground?

Switches should be grounded. If they're on a metal box, and firmly attached (metal of the switch ends actually up against the metal box), then they don't need a separate ground wire, because the metal box is (should be) grounded. If it's a plastic box, then they need to have the separate ground wire.

What happens if a switch is not grounded?

Going without a ground wire

When you screw the light switch in, it will make contact with the box, and as long as the box is grounded, it will pick up ground that way. If the box isn't grounded, the switch will still work.