I once had a wall wart style power adapter whose output side was a standard coaxial cable (like for TV). The reason was that the signal amplifier it came with

I once had a wall wart style power adapter whose output side was a standard coaxial cable (like for TV). The reason was that the signal amplifier it came with was built into the housing of a 2-way coaxial cable splitter, presumably because said housing was inexpensive and readily available. One of the ports that would normally have a second TV attached was instead repurposed to provide power to the amplification circuits. I shudder to think what it would have done if I'd run this directly to a TV, though.