hello there need some advise my bathroom do not have a fan and in the past had have some mold re painted the bathroom but reliaze this will not last long now my question do not have a switch in my bathroom have a pull switch light now there is a venting hole in the ceiling that vents through the roof can i cut a bigger hole and vent the fan through that pipe and also there is a gri plug in the bathroom with a 15 w breaker from the box can i put a double box and have a gfi plug and a switch that can turn on and off the fan and how do i do that thank you tony