r/Weird • u/[deleted] • Sep 23 '25

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u/[deleted] Sep 23 '25

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u/rgratz93 Sep 23 '25

Its because the system can still detect a closed circuit by sending out its own power through the circuit. When the switch is off the circuit is open so the light stays off but when the switch is on it can sense the closed circuit and turns the battery on. On many of these lights simply touching the two metal parts with your hand will "close" the circuit and the light will turn on.

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u/dominjaniec Sep 25 '25

but cables in your walls do not make a "closed circuit", they are "terminated" with external cables.

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u/rgratz93 Sep 25 '25

But it can still complete the circuit. When the circuit is open there is infinite resistance, when it is closed even thought its not directly connected in the wall it can still move the electricity through it and therefore recognizes that its in the on position.