Shelly duo's switch component topic configuration, here you can see the device configuration in order to turn on and off the light. Topic Responce shellies/ShellyBulbDuo-/light/0 Script: var data = JSON.parse(payload); return data.ison ? 1 : 0; ----------------------------------------------------- Topic Write shellies/ShellyBulbDuo-/light/0/command Script: return payload == 0 ? "off" : "on"; ----------------------------------------------------- Topic Event shellies/ShellyBulbDuo-/light/0 Script: return payload == "off" ? 0 : 1;