Yes is the answer to both questions. Wall fans are better than ceiling fans because the heat and moisture that is being pulled through the fan often causes problems in a cold attic. Ideally, a fan should run down and out the basement instead of up and out the roof. If you buy a humidistat switch and attach it to the manual switch, it will turn on and off automatically. The switch can be set to accept the desired amount of humidity in the room. When the humidity level in the bathroom rises above that set level, the fan will activate automatically. There are even some fans that activate with motion detectors.