I've got spots on my ceiling in one of the bathrooms in my house. There are 3 spots in a straight line. They are perfectly round and very small. I am thinking they are the nail heads as magnets stick to them. The spots are cold and seem lightly damp. I am thinking it is condensation on the nail heads as they must act as a conduit for the cold to come in from the attic.
How can that be fixed? I cleaned my bathroom fan and I think it's about 15cfm under the HVI recommendations. It was very dirty, so I don't know if maybe it's not drawing out enough humidity from the air?
What should I do?