This video demonstrates how to wire an ifm 2-wire AC capacitive sensor, but the same principles should apply for wiring any 2-wire AC sensor. The sensor shown here is the KI0202, and to correctly wire it, you'll need the sensor, a power supply, a relay (used as the load), a fuse and a fuse terminal, some spare wires, and the appropriate screwdrivers.
More information about our capative sensors: https://www.ifm.com/de/en/category/010/010_020
