Sonoff MQTT settings

  Topic = %topic% (sonoff)
    flagpole

  Full Topic (%prefix%/%topic%)
    /house/outside/%topic%/


Switches.yaml

- platform: mqtt
  name: "Flag Pole"
  command_topic: "/house/outside/flagpole/cmnd/POWER"
  payload_on: "ON"
  payload_off: "OFF"
  state_topic: "/house/outside/flagpole/POWER"
  retain: true