Door Repair For A Door That Won't Latch
I went to look at a door problem today. The customer was saying that the door wouldn't latch. Sure enough the door swung and closed great, but it just wouldn't latch into the strike plate. The problem was that there was a large gap between the door and the strike jamb that it latches into. Maybe when it was installed, there shims weren't used to square and plumb the frame. The door frame seemed to bow out so that the door's jamb was nailed right to the rough framing without shimming it first. Anyway, through luck or otherwise, the door swung fine, but just didn't latch.
So somehow the trick is to close the gap between the latch edge of the door and the door frame, without removing the trim molding and sinking a lot of time into the repair. You could shim behind the hinges which would close the distance, but this would make it so the hinges wouldn't be flush with the hinge jamb. Not good. I would leave the door alone since it operates well as is.
The other alternative is to remove the trim covering the strike jamb and goose the jamb out towards the door. Since this is an interior door, this would work fine, but you risk cracking the trim while removing it, as well as damaging some paint in the process.
The easiest fix is to remove the strike plate and shim it outwards toward the door, which closes the gap and allows it to latch. Remove the two screws that hold the strike plate to the jamb and you can put a washer (or several washers if the gap is very large) behind the strike plate and then just screw it back in, making sure the screw goes through the center of the washer to hold it in place. You could even use several thicknesses of cardboard in a pinch...a quick repair for a Las Vegas handyman.