Ron, corrosion is from any moisture getting to the metal surface, and in many cases can be the cause of what seems to be a serious electrical problem.The brass contacts are very easily corroded like this in many applications, especially in damp/ocean-like (salt water areas) climates. You can clean the areas with a " electrical contact cleaner", and mabye a small brush to get in there. I would clean them up, and use again, since there really isn't an issue with the rest of the components. You can even put a small film of penetrating oil on the metal contact surfaces. Just don't use WD-40, since it's not the best for elctrical connections. I have used a special grease for this purpose as well, but really not needed in your case.