Modular, Removable Doorway Plug System for Tight Spaces

The user describes a very specific and common architectural challenge: needing privacy at a doorway where traditional doors are impractical or unsafe due to space constraints. A product or a set of detailed DIY plans for a 'doorway plug' that is easily removable, space-saving (e.g., vertical slide, accordion fold, or tension-mounted panel), and offers privacy would address a significant unmet need. This could appeal to renters, homeowners with unique floor plans, or those seeking temporary door solutions without permanent installation or significant renovation.