Turn off electric power. In general practice the diagram above is most often used and is a good guide for wiring a new 4 way switch circuit.

Wiring Diagram For Sonoff Itead Wifi Light Switches In 4
Installing 4 way light switch. When more than three switches are needed you may simply place more 4 way switches between the three way switches. Do you need a 3 way switch wiring diagram. 4 way switches are a convenient way to operate lighting fixtures from three or more locations. Most 4 way switch wiring is placed between the wiring of two 3 way switches. Turn on the light or device being controlled by the 3 way switches if you already have them. So in short you would cut the wire in between the two 3 ways and install a 4 way switch.
Fully explained 3 way dimmer switch wiring diagram will take the mystery out of wiring a 3 way dimmer switch. Quick 4 way light wiring. All you have to do is find the 3 wire running from one 3 way switch to the other 3 way switch and install the 4 way switch between the two. 4 way switch wiring. Now thats sounds easy but you will most likely find that wire way to short to just cut it and install it in a new switch box. This is meant as a guide.
For a 4 way light circuit to work you need two 3 way switches and at least one 4 way switch. Return to location you plan to wire to verify that there is no electric flow to that device. Fully explained 4 way switch diagrams. How to wire 4 way light switch and intermediate switch in this video we explain how four way intermediate switching works to connect a light fitting which is controlled with three or more light. Connect both white wires together with a wire connector and stuff them back inside the wall box. Place all the 4 way switches between the two 3 way switches.
A 4 way switch wiring diagram is the clearest and easiest way to wire that pesky 4 way switch. Power from light fixture to light switch. Connect the pigtail to the ground wire on the four way switch. I have a few of the most common ways in wiring a 4 way switch to help you with your basic home wiring projects. If you want more than three locations to control the lights you will need a 4 way switch for each of those extra locations. Take a spare 6 inch length of ground wire and connect it with the two ground wires in the box so you create a pigtail.
Your wiring could be very different. 4 way switches are a convenient way to operate lighting fixtures from three or more locations. Starting with safety and understanding 1. If the device is still. When wiring in the 4 way switch it is most simply described as simply cutting the two traveler wires the two wires that go between the two 3 way switches and terminate on each switch and putting two wires from one switch on the top two terminals of the 4 way switch while putting the other two wires from the other switch on the bottom two terminals. 4 way switch wiring fully explained 4 way switch diagrams.