Hello, I own a mobile home that has metal siding on the exterior and I do have drywall in my bathroom. It has never had a exhaust fan installed in the bathroom but it does a have a window. However the moisture really stays in the bathroom which has caused some mold. I will be using mold control and painting with mold blocking paint but I wanted to prevent this from happening again. We usually open the window but in the Winter we don't and sometimes other people in the household forget which causes the moisture to stay in. What is my easiest option? 1st idea - Is there a type of fan I could just put in the window and run an extension cord to? If so would I be able to leave it in the window with it open all the time is there a way to prevent the rain from coming in? I think this method would require putting the fan in and out and closing the window which would result in someone continuing to forget to do it. 2nd idea - is a wall mounted exhaust fan but I do want to do this the easiest way that requires less work. I have drywall and I don't really want to mess my walls up too much and creating more work. I do have a light fixture above my vanity. It is kind of too large and bright with the amount of bulbs so I was thinking of putting the exhaust fan there where the electric is already at and adding a smaller light??? What do you think?