You'll never guess what was causing the excess moisture! This is my 2nd winter in the house and I'm still learning about it. My water softner discharge line was connected to a 'T' joint, which then went into my sewer line. Connected to the other side of this 'T' was the drain line from my furnace. The force of the discharge from my water softner pushed the water backwards into the drain line for my furnace. This water then went into the duct work which begins under the furnace. Every time the furnace came on, the hot air moved past all the water in the duct work and moist air went all through my house. I have since installed a seperate drain line for the water softner. Thought this strange enough to share.