Slice the lemons in half and squeeze the juice into a spray bottle. Add an equal amount of water so that the solution is half water and half lemon juice.
Spray the lemon solution in the closet area where the mold or mildew smell originates. Do not saturate the carpet and closet walls, but spray them lightly until you notice the lemon scent in place of the mildew.
Let the area dry for an hour or two. Reapply the solution in the same manner if the odor persists.