ok. i have an 850 square foot condo. for sometime, i have noticed blackish walls right around the window frames of the 2 windows where my TV set is in a corner. I wipe the walls occasionally and black does come off on my paper towels. I have 6 other windows in my condo also. No blackishness at all. Just where my TV set is. Does anyone have any idea why? Can the static from the TV set attract more dust and dirt or something? I vacuum every 2 weeks. Is there something I can do about this? Thanks, Rita