Stop in for a cup of coffee

Both my Wife’s Durango and my Jeep do this occasionally. Check your ground on the battery and again on the Engine and PCM grounds. Then if all those are good, check and make sure your tin heat shield near the starter hasn’t been hit by debris and knocked against the starter relay studs. My Jeep is bad about that happening with the thru the forest and over the hills off roading I do
OK, but how does that cause the horn to go off intermittently? And even if it can,
wouldn't that cause other issues too?