This video demonstrates how to control one light bulb with four two-way switches, showing the wiring connections for the bulb and the switches to neutral (N) and live (L) lines . It also includes a warning about 220V AC danger . br br ⚠️WARNING... br br The videos are for educational purposes only. A high voltage can cause serious injury. It is possible for some works to be dangerous. And for that, you don't risk and damage yourself. I am a professional in my field. Before you attempt the experiment or work, you must take care or take precautions.