Light switches tend to be bistable devices, equally at home in either the on or off position.
Certain people, especially in my experience teenagers, tend to be unaware that they have left roomlights perpetually on.
Today’s invention is a reminder to switch off the lights but which also includes a couple of supportive ‘nudges.’
A lever is attached, using a sticky pad, to a switch, so as to make it physically more difficult to activate the lights than to deactivate them.
Deactivation is actively encouraged by providing a small, glow-in-the-dark hand which a departing teenager is marginally more likely to high-five.