How to wire a 4 way light switch with power feed via the light switch
In this 4 way light circuit the power source is via the first switch (SW1). The hot connects to the common on that switch and the neutral is spliced through all the switch boxes to the neutral terminal of the light. A Three-wire cable runs between all the switches connecting the travelers.
A two-wire cable (C4) connects the last switch (SW3) to the light fixture, the common on that switch connects to the hot terminal on the light.
Tags: 4 way light switch, 4 way switch, crossover switch, Four way switch, how to wire a light switch, Power feed via switch, travelers