I'm not sure if this counts, but at one time I worked in a furniture mill.
We had one machine called the "RF Machine" or "Radio Frequency Machine". It was a big microwave for gluing wood together. Whatever they were laminating, they'd run glue along the edges then push anywhere from one table top to a whole pile of legs into the machine at once. It would press the pieces together and hit them with the microwave for about a minute at which point it would shove a sticky mess out to be thrown on pallets with sawdust thrown between to keep them from sticking. Thinking back, a lot of manual labor.
Anyway, the interesting part of the machine was on the back side, outside of the machine, there was an ordinary florescent light tube sitting on a wire rack. No wires going to the tube. The RF power from the machine lit up the tube without wires and the person tailing the machine knew it was turned on.