I took a metal rake and ever so lightly scratched the wall with it. Dan's head popped up. His eyes got big and he ran out of the barn. You may already know the story. Girl has fearful horse.
Girl clicks horse.
Horse learns how to be brave. Alexandra Kurland recently wrote a nice piece about spooking and how to help the horse to control his body when a spook overtakes him. This also applies to asking my horse to relax when he hears a click. He must be taught how to do it. Survival runs deeply in the horse and fear is it's natural counterpart.