Smart meters do not need to be plugged in manually; they are hardwired into your home's electrical system for continuous and hassle-free monitoring. It requires only a power source. The sensor performs its own modulation, demodulation, amplification, and output switching. Some self-contained sensors provide such options as built-in control timers or counters. Connect the black wire from the photocell to the black wire from the switch using a wire nut. The installation process typically involves the following steps: Connect the. Wiring a photoelectric switch, whether it's on its own or into a light fixture, first requires that you shut off the power supply for the circuit so you can work safely. They use minimal energy that the utility company provides.