This guide will let you know how to make a Light Switch in the Minecraft game.
The first thing you need to do is to place two droppers on the ground and a hopper in front.
Then you need to add a redstone comparator on the hopper and a redstone lamp just next to the hopper.
The next thing you have to do is to add a stone button at the back side of the dropper. And add gray concrete blocks in the dropper. Press the stone button to make it work.
Add one more redstone lamp on the ground and a stone button at its back side. Press the button to light it up.