A repair plan will most likely involve closing off any ventilation grills
with sheeting and duct tape and shutting down your furnace so that the
blower doesn't spread spores and dust throughout the home, as well
as removing everything - furniture, pictures, lamps, etc. - from the affected room.
A most effective way to contain the affected area is to tape poly sheeting
on all four edges of the door opening and having a slit cut up the middle
from top to bottom.
If the moisture source is due to previous or recent water damage (such
as a burst pipe or hurricane damage), contact a
water damage mitigation expert.