Final answer:
A three-way switch is an electrical switch used to control a single light or set of lights from two different locations. It is commonly represented by an S with a 3 next to it.
Step-by-step explanation:
A three-way switch is an electrical switch that is used to control a single light or set of lights from two different locations. It is commonly used in staircases, hallways, and large rooms. One of the most common symbols used to represent a three-way switch is an S with a number 3 next to it, denoting the three-way functionality.
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