High Voltage input and output microcontroller
I think all microcontrollers operate on 5 volts or less, and all inputs/outputs are also 5 volts or less.  It is very common to have level translators between the microcontroller and whatever it is controlling.

To control 120 volt (or 230 volt) AC devices, you could use a mechanical or solid state relay that could be driven by the microcontroller..