Is there any way to check for tears in the AC "lines" (the tubes) from the
inside? I think I have wasps in the attack and they have found a small tear
in the "lines". Consistently only happens upstairs.

Have had AC company check, but some of the lines are buried in insulation
and cannot be checked from outside. I have tried dusting attic for bugs but
wasps seem pretty hard to kill off. Cannot see nest anywhere but they come
and go around intersection of roof and "facings"

Hope this makes sense..