I had this happen with a '96 Sebring convertible. Middle of the night I hear something that was hard to locate at first. Car is inside a garage attached to the house via a breezeway. No neighbors, so no issue there. Once I found the noise, I pulled the fuse. Next day I did some more checking and apparently the module in the steering wheel went bad or got warped. Every time I put the fuse back in, the horn sounded. I found and pulled the horn relay and left it out. I never use the horn and we don't have inspections here.
No way I was going to mess with the steering wheel with the factory included bomb.
Sold the car that way too. No idea what the next owner did.