u/-m-i-s-f-i-t-

Some of the old drywall is starting to do this in small spots on the ceiling in the hallway and one room, not sure how old but this is becoming more and more common throughout the old drywall areas.
A contractor I use for projects said it's old and either needs to be scrapped, floated and retextured or replaced.

Some info.
This is an 1960s house.
Old blow in insulation in attic
Weather is Hot and Humid, 80% of the year.
Attic is well vented.

Im honestly just posting this to see if anyone else has had a similar issue and if there was a underlying cause.