Horn button came off, can't get it to stay on

[dgheinen]

Like the title says, while driving today my horn button came off on the freeway,
which meant I was scrambling to grab the contact and try to keep it from blaring while I was driving. I ended up removing the contact wire in the meantime while I try and fix it.

The inside of the horn button/cap has 3 indents that I assume are meant to grab the horn contact, but for whatever reason it won't anymore. Is there a different style of horn that I can use, instead of this crappy one? Thanks in advance.