Nothing demonstrates how much dust and other particles are in the air like taking down a picture from the wall. The clean spot where the picture used to hang speaks volumes. Unfortunately, there's no quick fix, because the spots where the pictures were located are the clean spots on your walls. It's the film that covers the rest of the walls that must be removed. What your walls really need is a complete washing or repainting.
Things You'll Need
Murphy's Oil Soap
Ladder or stepstool
Remove all remaining pictures and other items from the walls, and remove the furniture from the room, if possible. If not, move all of the furniture to the center of the room, away from the walls. Cover the furniture and put waterproof tarps down on the floor.
Mix the Murphy's Oil Soap with water according to the directions on the back of the bottle for washing walls.
Dip your sponge or rag into the soapy water and start washing your walls. Start with an area where the frame spots are located and wash over them, along with the surrounding area. Let this test patch dry completely, then determine if the frame spots now match the rest of the wall.
Wash the rest of the walls if you were satisfied with the results in Step 3. If you were not satisfied, finish washing the walls and let them dry thoroughly so you can begin repainting them. Some people paint over dirty walls, but the primer coat and paint adhere better if all of the film is removed from the walls first.
Allow the newly washed walls to dry thoroughly.
Apply the primer coat and sufficient coats of paint if washing the walls did not solve the problem. Make sure to open windows or bring in an exhaust fan to ventilate the room before you begin painting.