Found in 90s Popular Electronics, this circuit fires a load through a MOSFET from an audio signal applied to the input. Power supply is done according to the load.
We found this parking light circuit for automotive use in a Texas Instruments optoelectronics...
This counterphase circuit is from a 1973 publication, and can work with mains voltages or 12 V....
Suggested by General Electric in 1966 documentation, this circuit uses unusual components today....