removing permanent marker from paint wall

Acetone will do it. But before you use it, try it on an inconspicuous area first – it attacks some paints (mostly acrylics). If that’s an issue get your hands on some isopropanol (electronics store). It won’t work quite as well as the acetone, but it will work. Another approach is to rub over it with a whiteboard marker and they spray sugar soap or a window cleaner on it before wiping it away