How can a light switch be wireless and battery-free?

The act of pressing the switch creates the energy. Not only does this switch not use a wire, it also doesn't need batteries! Inside the switch is a magnetic coil, when the switch is pressed a minute amount of energy is created and used to send a radio signal to a receiver. The switch doesn't store any energy, it creates it and instantly uses it. The switch has been tested to last through 20 years worth of clicking so it's maintanence free and very reliable.