It doesn't help you now, but it's probably a good idea to have something absolutely unique about your house or apartment so the guys can't mistake it for any other door.

"Only knock on the door with the red teddy bear decoration hanging from the doorknob."

Of course, the stupid guys are still going to knock on the wrong door anyway, but maybe it will improve the odds. Make sure it's something unmistakable and emphasize to the guys that they should only knock on that door.