Sagging Door Shift: Door Bottom Drags and Rubs on Floor From Use Over Time. Rubbing at Corner at Top or Bottom Door Bottom Rubbing, Drags on the Floor.
https://www.youtube.com/watch?v=T1oTxbac_-M
If your door bottom is dragging or top is rubbing because it’s sagged over time, longer screws into the stud at the top hinge is one of the quickest and cheapest fixes, and it works well.
Over years of use, the screws in the top hinge loosen or the wood compresses. The door tilts slightly, so the latch side drops and drags. By replacing two or more ¾ inch short screws in the top hinge with 3–4 inch longer ones that bite into the wall stud. This pulls the top of the door back toward the hinge side, shifting the bottom corners.
Support open door with a book wedge under the latch side. Remove two Screws from the top hinge at closest to the doorstop trim is best.
Replace with a Longer Screw – deck or drywall 3-4 inch wood screw. Drive the Screw In so it catches the wall stud behind the jamb. Tighten until you feel the hinge snug and the door lift slightly. Open/close to check for drag or catch. Look to see the latch side alines with bolt.
Don’t replace all the hinge screws at once — one at a time keeps the door aligned. If the hinge mortise is worn, slip a thin cardboard shim under the hinge before tightening. If the screw hole is stripped, pack it with toothpicks and glue before inserting the long screw.