Sounds like you want to step down power line voltage or step down 'stepped up voltage', take alook at your power line coming in to your house and follow it back to the huge transformer that is the easiest way to step down voltage.
the former will be huge from 5kVAC down to 240 VAC at 6.6Amps, for that requires about the size of a substation. We are talking High Voltage HV transformers.