Not sure what brand you're dealing with so what I have to offer may be incorrect.. Just looking at the wire, it appears you can use the original factory cancel cam. The plug on that wire just goes into the original cam and with a twist, locks into place. The other end attaches to the horn button assembly that came with the wheel.. I have a Lecarra wheel and that's how it works on my '71...
https://www.classicindustries.com/pr...ts/cx4876.html