Water leaks are more obvious as telltale signs such as darkened water stains evidence of mold on the ceiling inside the house or wet sheathing.
Everything in my attic is wet.
Clothes dryers venting air to the attic rather than outside.
Attics can suffer two types of leaks.
Water or drip marks scattered on the attic floor.
Moist air is created from everyday activities including cooking.
Buckled or damaged roof sheathing.
Air conditioner condensate pan not draining.
Moist or wet insulation.
Moisture frost and ice buildup on roofing nails.
Top causes of attic moisture.
In the first instance you need to try and reduce the amount of moisture vapour penetrating into the attic in the first place.
Inadequate ventilation attics must be vented to allow moist warm air to escape.
Firewood being stored in the attic firewood contains moisture that will.
Moisture or frost on the roofs sheathing.
Though attics are typically hot and dry a leaky roof or pipe condensation or severe weather can cause water to enter your attic.
My guess is that this has been going on for a while and is caused by convection of living space moisture into the attic the most common source of attics excessive moisture.