Motorcycle Repair: 1982 Nighthawk horn stays on, horn button, volt meter

Question
Just bought the bike. It is mint. Noticed the horn was a bit weak. Washed the bike on Saturday. Today the horn started going off by itself (with the key on of course). It turns off with the ignition being turned off. The horn becomes slightly louder if you push the horn button. The  inside of switch is clean and I still could not shut off the horn after dismantling the switch. Fuse is clean and good
Finally yanked the leads. Is the horn hot all the time? bad contacts on the horn perhaps? Since it is buried under the tank I could not see it very well. I put a volt meter on the leads and there was about 10 vdc coming out constantly. This has now gone back to 0 vdc unless you push the horn button. And of course the bike is going in for certification shortly and now this. Any ideas? Thanks

Answer
The black wire to the horn is hot all the time.  To activate the horn, you have to ground the circuit with the button on the switch. When you got it wet, the circuit found a path to ground and the horn started to blow.  You'll want to track it down because it could happen again when you ride in the rain.

Good luck
Rich