Removing the Source of the Smell
Locate the source of the smell, looking for the thin, fuzzy coating on surfaces that the fungi cause. Open a window before proceeding. To remove the mold/mildew, pour into a 1-gallon container 1 cup of chlorine bleach and fill the remainder of the bottle with water. Place the cap on and shake gently to mix the bleach and water. Pour some of the solution onto the mold/mildew and with a brush or pad and scrub until it is totally removed. Rinse with clear water and wipe dry. Move on to the next spot and repeat.
If you can't locate the source of the smell visually, walk to where the smell is the strongest. The mold/mildew may be hidden behind a wall, sink or tub. You may have to remove a portion of the wall or a piece of equipment to locate the source of the smell.
Drying Out the Area
Leave the window open in the area where you have removed the mold/mildew. Open other windows and doors to help air and dry out moisture. If any curtains or other fabrics are present in the affected room, remove and wash them. Add ½ cup of chlorine bleach in each load of white fabrics and ½ cup of pine oil disinfected solution for color fabrics. After you have removed any curtains and fabrics from the problem area, spray the room with a sanitizing spray and leave the area immediately.
Returning to the Area
Place curtains and other fabrics back into the room after the musty smell is gone. Purchase and install a dehumidifier or room air conditioner in the area if the odorl returns. These two devices will help dry out the area and stop mold or mildew from forming. Also, check for leaky pipes in the area. Heating the area will also remove moisture and stop the formation of mold or mildew.