Why does one light flicker when you turn another off?

A light flickers when another is turned off due to a sudden change in voltage within the electrical circuit. This can happen if the lights are on the same circuit and the sudden drop in current causes a momentary surge or fluctuation that affects nearby lights. Additionally, issues like loose connections or faulty wiring can exacerbate this effect, leading to visible flickering. Ensuring proper wiring and circuit load can help mitigate this problem.