You will require maybe a piece of thermocol or applied like I have one safety pin and two thumbtacks. These are the board pins that you use. Take this safety pin and fix it onto the ply. It should be free to move. The other pin you place in such a way that it touches it. This gap should not be very much not too wide and should take care that the pin touches it when it is brought close to it here. Now, the rest of the circuit can be assembled around it. For example, I have here, I have a circuit here. This is a cell. This is the bulb. The wires are connected. This is one end. This is the other. So, the circuit is not complete. Let us connect one end of this wire to the switch that we have made, the other end to the other thumbtack. And let us see if our switch works. And I connect these to the bulb lights. This is on off off off off off. By choice I can let the bulb glow or put it off. So you have just learnt a very simple way to make your own switch. Now, the switches in the house are also working on the same principle. Make the circuit and break it. But of course, they are little more complicated in design, but work the same way for your devices in the house.