If your lucky and it is a steel door you can buy strong enough magnets to hang stuff. Lee Valley Tools have a great assortment
How do you hang a prelit wreath on a door that opens and shuts?
You don't, unless it is battery operated. Hang it next to the door or inside .
Reply:They make hangers that go on the top of the door. These will still allow the door to open and closed.
Reply:there are battery operated strings of lights out there if you can find them