If it's a home without pets and not a lot of foot traffic, once or twice a week is usually fine. But if you've got pets - especially ones that shed - you'll want to vacuum at least every other day, if not daily, in some rooms.
"Ghosting occurs when damp air and airborne particulates, such as dust or soot, condense on drywall in streaks or lines. This phenomenon is typically caused due to thermal bridging."