(June 22, 2019 at 7:15 pm)arewethereyet Wrote: Is something inside it? Maybe a squirrel or something found it's way in and can't find it's way out.
No, it isn't a roof exhaust port. It is a side port which also has cover so rain won't get in. It stopped now so it is most likely simply a difference in air flow' temperature between inside and outside.