How many three way switches are required to turn a light on or off from two separate locations?

To turn a light on or off from two separate locations, two three-way switches are required. A three-way switch allows for the control of a single light fixture from two different points. Each switch has three terminals and can alternate the flow of electricity, enabling either switch to complete the circuit and turn the light on or off.

When you install a lighting system that involves two separate locations for control, one switch is placed at each location. This configuration enables seamless operation of the light fixture regardless of which switch is used, thereby providing the necessary functionality for controlling lighting in areas such as hallways or large rooms.

In contrast, the other options do not provide the capability needed for controlling a light from two locations. One switch would be inadequate as it does not offer the multi-location control feature, while three or four switches would unnecessarily complicate the system beyond what is needed for simple two-point control. Therefore, using two three-way switches is the most effective and standard method for achieving the desired outcome.