The switch actor is used to control binary on/off switches. Internally, it's a ../generic2/index, but with a much simpler configuration, namely none at all.
Note
It calls the generic homeassistant.turn_on and homeassistant.turn_off services and hence can as well be used for other entity types supporting to be turned on and off this way. However, they need to provide "on" and "off" as their state.
Especially, this is true for input_boolean and light entities.
For completeness, this is the configuration you had to use if you wanted to build this switch actor out of the ../generic2/index yourself:
generic2-config.yaml
You need to return the strings "on" or "off" from your schedules for the switch actor to work. It's that simple.