I use two switches. There are switches with built in motion (GE) but I am not aware of any with built in humidity. In either case, the switch location is probably not optimal for either type of sensing. I would suggest a Zigbee sensor for both motion and humidity, they seem to be faster than Zwave sensors in general.
To turn the fan on, I use an app called Smart Humidity Fan. It is available for either manual install, or better yet use the excellent Hubitat Package Mangager app that has this, and many other very useful apps/drivers. HPM can automagically install and keep many of your apps/drivers up to date.
