During windy times the wall in my bedroom squeeks. I deduced that the house being 30 years old, had drywall walls & this one must have bowed. I decided to get drywall screws and catch the studs. I did that and the problem was corrected. A few days later, on a very cold day, I noticed sweating at the bottom of the wall and some signs of mildew, suggeting this condition has been happening for a while. The house is a "RANCH" so I checked in the basement but the corner seems dry. The wall is an exterior corner wall. Any thoughts as to how to approach this problem? Thanks in advance for your help.