There is a seam in our upstairs ceiling where the drywall tape is peeling up. I know I can repair this, but I am worried about the cause. It's just in one little section, maybe two feet long, right above this ceiling is the attic. Should I be looking into attic humidity levels? Is there a way to test that? Our attic has a vent on the side but no roof mounted vent. I just want to make sure I'm not covering up a potential problem by repairing the dry wall tape.