Alfonso Ribeiro -- I Broke Up the Dumbest Fight Ever

Alfonso Ribeiro says he sprung into action to break up a barbershop fight in Hollywood last week ... because he didn't want to get SHOT!!!!

The former "Fresh Prince" star was at Katsuya in Hollywood last night when he explained the whole thing ... insisting the fight was simply, "Two real dumb people having a dumb argument."

Good news -- he didn't get shot.
Bad news -- he's gotta find a new barber.