That's where 3-way switches come in.. Unlike single-pole switches, which control lights from one location, 3-ways work in pairs. You must have two of them — and only two.

Step 1: Locate your switches The most basic three-way switch setup has two switches that connect and control one light fixture, like switches on either end of a hallway, staircase or large living ...

The smart switch is designed to replace either a single-pole or three-way switch, and its minimalist design makes it one of the best-looking switches on the market. Read more Smart Home; ...

The simplest setup is to have just two three-way switches control one light. A three-way switch has three screws on it, plus the green grounding screw.

A one-way system for light rays could allow optical computer chips to overtake their standard electronic counterparts. The new device should eventually help to improve the speed of data processing ...