I promised I would explain the whole thing about wireless light switches (a.k.a. a two way switch)…
You requested details about this “mysterious” and otherwise “magical” technology that is seriously misunderstood. If that describes your curiosity, please read ahead…
Wireless Technology
There are two main pieces to a wireless light switch set up: the transmitter and a receiver. These two pieces of technology are the only things that are needed in turning a standard light fixture, or load, into a wireless manifestation of the same function.
Transmitting a Wireless Signal
In this whole thing, the transmitter is the most interesting puzzle piece. The transmitter is the device that sends a signal to the fixture to turn on and off. When you press the light switch, this will shoot a signal via radio frequency to the receiver. The receiver will interpret that signal and turn the load off or on, depending on the opposite state of the fixture. The transmitter is the part of this wireless technology equation that is actually wireless. This is the most important thing because running a wire to a light switch is the biggest pain in installing a switch.
Powering the Transmitter
The transmitter in a wireless light switch needs to receive its power from another source. Cheaper brands solve the issue through batteries. The problem with that is that batteries run out and there is no way of knowing when it is getting close to that time.
The other two possibilities are solar power and kinetic energy. Solar power is used primarily in transmitters that are hands free, like an occupancy sensor. An self-powered occupancy sensor may still need a battery for backup, however, most of the time, the solar panel will do the trick.
The final possibility is kinetic energy. The manufacturers of the light switches create little modules inside of the switch that create some resistance when a user presses the transmitter. The force against this resistance is what create just a spark of energy – just enough energy to send one tiny little signal.
The Receiver
The receiver is the part of the setup that does require wiring. However, no additional wiring is needed. Instead, you can simply replace the old light switch with the receiver, wiring it in its place. You could also place the receiver basically anywhere in between the breaker and the load. However, it is recommended that you place them at a junction box. The receiver picks up on that RF signal and tells the light fixture to turn on or off.
Conclusion
If this felt too long to read, just know this – there is a transmitter (wireless) and a receiver (wired to circuit). The transmitter is the light switch and can be placed anywhere you want in a 150 foot radius. And while the receiver is wired to the circuit, no additional wire is needed in the installation. The most typical application for this answers the question, “How to move a light switch?”