Be careful not to cut the door too deep or too far.
Interior door suddenly now scraping floor.
First run a piece of paper at the bottom of door to identify where is sticky.
Sandpaper can be used for small rubbing problems while the belt sander or circular saw are ideal for more extreme door sticking issues.
First check that everything is square.
Houses settle over time which often causes a door to sag inside its frame.
Adjust the top hinge 1 use a screwdriver to tighten the screws in the top hinge on the door and frame.
A dragging corner makes a door difficult to open and close.
Use a pencil or a label to mark where you need to sand down.
The dragging door corner can scrape the floor or threshold.
Can you tell which it is.
Over time these screws can work their way loose causing the bottom of the door to drag on.
Assuming the hinge screws are tight it may be that the only way to permanently fix the problkem is by rebuilding the door frame and or fix the slope in the floor.