Horn continuously goes off. Pulled relay.

Have a 2000 accord 4 cyc. Horn continuously goes off. Pulled relay. Brought to Honda. They say they have not seen this??? They swapped the airbag with a civic and said it solved problem. Wanted $1150 for new airbag. I did not do this there. Bought an airbag off ebay (used) for $90, installed it and then the relay. all was good until I pressed the horn in car. Switch engaged and latched on... Continual horn again so pulled relay. No idea what to try next?