|MLA Citation:||Bloomfield, Louis A. "Question 808"|
How Everything Works 19 Jan 2018. 19 Jan 2018 <http://howeverythingworks.org/print1.php?QNum=808>.
But when you turn off the light switch, you open or break the circuit. One of the wires connecting the power company to the light bulb suddenly has a gap in it and the current of electric charges can no longer flow. The switch itself actually contains two separated wires and a mechanical device that connects them only when the switch is in its on position. The precise structure of the mechanical switching device differs from switch to switch, but the behavior is always the same: the switch disconnects the two wires—and thus breaks the circuit—whenever you turn the switch off.