Horn keeps getting stuck on 1994 Mazda Protege

my horn goes off randomly through out the day. It goes off when Im driving and sometimes even when it is parked. The only way to stop it is to bang on the steering wheel. This morning it went off and I banged on the steering wheel and a piece came out from under the steering wheel cover. Its a flat piece of metal light gold and it had a king of D shape. Does any one know what this piece is and how to solve this problem? Thank you!

Asked by for the 1994 Mazda Protege
Need to remove steering wheel and see what broke off the horn contacts inside, when grounded by you push button the horn goes off so now the exposed part is grounding intermittently.