When I first bought my Mav I found that the rubber horn piece on top of the steering wheel kept coming off. When it fell off the steering wheel one of the pieces that sticks under the copper tab kept coming out from the tab and the horn would go off. When I got home I put the piece back under the tab and replaced the rubber top piece. About an hour later the horn was going off. I took the rubber piece off and took the end out from the tab and it stopped. I got a NOS switch assembly hoping then when installed the tabs keep the ends down. Should I look into getting a new rubber top as well Cause the old one wouldn't stay on? Will replacing the switch assembly fix the problem? Most important does this make sense?
Replacing the horn switch should be the correct next step in fixing this. I would bet your original got bent, perhaps when the tab did pop out of place. It may have already been a problem prior to buying the car, and that might be the reason for the cover being loose ... someone might have been messing with it, trying to fix it. Replace the cover? ... depends on what shape it is in. I haven't messed with a stock wheel in a long time and only vaguely recall how they go together. Perhaps a picture would tell us more. If this doesn't fix it, the problem is deeper in the steering column, but going by your description, it is a really solid bet that the switch will fix it.
I replaced the horn switch in my Comet about 90 days ago. My switch had deteriorated to the point of crumbling and the cover would no longer lock in place. (The horn blowing MCCI Mini Meet event through the streets of Geneva-on-the-Lake here in Ohio was the final blow for the switch. Pun intended.) I got my switch from Auto Krafters however, the price is over $100. I used my old cover. Now it operates and looks like new.