Seventy five years ago this month, the June 1951 issue of the British publication Radio Constructor carried this idea for fabricating a switch that would turn a circuit on when the lid was opened. It was originally built for a cocktail cabinet, to turn on the lights when the lid was opened. But the author noted that it could be used for any circuit.

The cost was basically zero, since the author used an old volume control which was going to be thrown away. The volume control itself was not used (in fact, the slider was removed to make it turn more easily). Instead, only the switch was used. A spring held the switch in the off position, but when the lid was raised, the spring stretched and allowed the switch to rotate back to the on position.