I assume this is condensation, but is it something I can fix myself? It is only happening on one vent as far as I can tell. It is on the ceiling (by far the most difficult vent to reach in my house!)
can you get into the attic above it? If so go look from that side.Counterpoint said:
Dang. I wonder which is cheaper, buying a much taller ladder so I can safely reach it or just calling an AC guy?