Video narration
When you flip a lamp switch, does electricity start there and travel to the bulb? In a lamp, a wire connects its power source to the bulb, and another wire returns directly to the source. With the switch open, there's a gap, so the path is broken and the lamp stays dark. Flip it, and the switch joins the two sides. That's the turn: the switch doesn't send a fresh stream of electricity to the bulb. It completes the circuit-the unbroken path-so the source can drive charges already in the wires. Those charges move through the loop, reversing direction repeatedly in household wiring. They aren't used up in the bulb; instead, they transfer energy to it. The bulb changes that electrical energy into light and heat. So no-the switch isn't where electricity begins; it lets the lamp's source power the bulb.