You need to read the first couple post in this topic:
Specifically @dalec reply which is the 3rd post. (I think)
I did something similar. I think I put a GE 12722 light switch in the wall and the GE fan switch 12730 stuffed inside the fan shroud/ box in the overhead. Has worked very well. Just have to use a phone or another device to control fan. I use our echo 90% of the time.
Hope that helps