In your case a attic access hatch or doorway is leaking badly allowing quantities of water laden air to come in contact with your roofing nails.
The nails in my attic are dripping is this normal.
A point often overlooked is that since it s winter the water freezes on the cold nails.
Some times here when the attic gets cold enough there will be enough moisture put into the attic that you will see ice on the nails and frost on the sheathing.
Old tar paper wood chips nails dust you name it.
Those fans need to go out of the house for sure.
But that rarely happens.
The nails that you see in your attic get as cold as the outdoor temperature.
Exposed roofing nails in attic dripping post by tnaval fri dec 29 2017 8 29 pm besides a table saw and a chop saw i used for a couple hours and my body heat.
If there is excessive moisture accumulation in your attic it will condense on cold areas mainly on the underside of your roof deck.
There may be no vapor barrier in your ceilings allowing the water vapor to pass into the attic.
The air in the attic has water in it and it condenses on the cold metal.
Tonight my wife and i thought we smelled smoke so we got to looking and eventually decided it was coming from a recessed light in the kitchen.