Converting a two-way light switch to a three-way light switch is a great way to solve common problems with light switching. A regular two-way switch allows a user to turn on the lights at one location only, while the three-way light switch allows you to turn the lights on and off at two locations with ease.Click to see full answer. Also question is, what is the difference between a 2 way and 3 way switch?A two-way switch (2 connections to the switch, not including ground)turns lights on or off from 1 location only. A three-way switch (3 connections to the switch, not including ground) can turn lights on or off from 2 locations. how a 3 way switch is wired? Three-way wire(which includes red, black and white wires) runs from the switch on the left to the switch on the right, with the white wire carrying ground and the red and black wires carrying the output from terminals in the left switch. Normal sheathed cable runs from the right switch to the light. Also to know, can a 3 way switch be used as a 1 way? Yes it can work. 3-way switches are spdt (single pole double throw) with 3 screw terminals, and regular switches are spst (single pole single throw) with 2 screw terminals. Just pick the correct two contacts and you are good to go. . A multimeter is the quick way to figure out which terminals to use.When should you use a 3 way switch?A light or lights can be controlled by more than one switch. The usual practice in home construction is to use 3-way switches. “3-way” is the electrician’s designation for a single pole double throw (SPDT) switch. The switches must create a complete circuit for current to flow and the bulb to light.