Just an update on the situation. This morning, nice temps. here, no humidity. I go out for a nice lunch, go home and BINGO. The room stinks like fireplace. It is hotter and more humid here and the ATTIC EXHAUST FAN IS ON. I should note, it is a small round exhaust fan. So, since the fan is hardwired, I disconnect it and will see what happens tomorrow. What is extremely confusing to me is that there is a damper on the flue at the roof and a pillow inside, yet the the room stinks. So, let's see what happens? Also, any other advice is appreciated!