My horn goes off by itself when I'm not in car. How do I stop this? on 1999 Ford Escort

The horn goes off at all hours. I have disconnected the negative battery cable so the horn doesn't bother my neighbors. The only way to stop the horn from blaring is by hitting the horn on the steering wheel repeatedly. What's wrong with the horn.

Asked by for the 1999 Ford Escort
Have a mechanic remove the air bag/horn actuator to see if it can be repaired. May have to replace it.