I don’t remember how I got it, but I’ve had this old project my Dad built back in his college days. He built it as an experiment in wireless power transfer, or WPT. From Wikipedia “WPT is the transmission of electrical energy without wires as a physical link. In a wireless power transmission system, a transmitter device, driven by electric power from a power source, generates a time varying electromagnetic field, which transmits power across space to a receiver device, which extracts power from the field and supplies it to an electrical load.
Built out of an old metal case, it’s pretty well designed with wire wrapped around a mason jar to create the electromagnetic field. A small light bulb is soldered onto another coil. When the light bulb coil approaches the magnetic field, electricity is transferred wirelessly, lighting the bulb.