I have a device to control (on/off and) the rpm of a fan located on top of an air vent on the roof of my house. I am not sure 'speed controller' as google translate suggests when translating from Swedish covers the functionality of the device (it's not a dimmer)? Anyway. I have not found any such devices with built in zigbee functionality, so I thought I might ad an on/off device with zigbee functionality to the powercord of the speed controller while keeping the speed controller on a desired rpm. The goal with this excersise is to connect a humidity sensor from the shower room to Hubitat and then control the speed controller to the roof fan using the zigbee on off/device. I am not trained in electirical things. What do you experts say, could it work?