I guess it is a good thing I do a general maintenance check before running the a/c and the furnace each year. The furnace/air conditioner guy had apparently removed about a ton of nesting material before getting to this. Allegedly it is a mouse that chewed through several of my electrical wires in the unit. All I know is, it SMELLS VERY BAD. Hopefully the smell will be all gone before we run the a/c this summer. Yewh.