It may help to have a small sticker or signage on a gun owner’s front door that displays the fact that the y own a gun and even describes what level of trigger-attitude the person(s) in the house have. This would help anyone who might approach the house, have a better idea of what to expect when ringing the door bell. Maybe use colors or numbers to show how the house owner feels about how they may react to someone who comes to their house—uninvited.
Level I could mean that the gun owner is very likely to answer the door with a shotgun in hand. Level II would mean they have a gun and are not afraid to use it. Level III would mean they have firearms training and have a reasonable view about anyone that they do not know, may, ring the door bell without getting shot.