Was a plastic sheet put between the sheet rock and the 'outside'? There are ways to build below grade, and that's one necessity. Now I'd want to know if the rest of those walls (outside the room) were constructed properly.

Any vents or air circulation?

I hope you mean DEhumidifier.......

Oh yes wantoretire I meant dehumidifier! When they constructed the safe room they did the moisture barrier but we did not put a vent in the room. So that might be what our problem is, although, we don't run the air or heat in the basement because it stays around 75 in the summer and 68 in the winter. I did go look in the other 2 rooms that were not finished and I have mildew on the legs of my furniture. The rest of the basement is finished. We have a bathroom, bedroom, exercise room, and the living room and kitchen is one big room. No problem in those rooms.

in all honesty, the cheapest solution it to leave the door open to allow air to circulate.