I have my fan and wall light connected to a single switch.so when I turn light on ,the fan goes on. I want to put a double switch in and have one switch control the fan and the other the light. Keep in mind the fan is not a part of the light. Fan is on ceiling, light is on wall

Do u have a window in in bathroom? Some areas require a fan to go on with light if there is no window.

What box or fixture is power going into?

With this info will be able to help u.

Chuck