[Bruce Colby]

If you run the lights through the ignition, you’ll be adding around 15 amps to that circuit. If you have extra lights or high power lights, it will be more. I suspect the switch isn’t designed for this much current. Certainly the old ones with the paddle-shaped, vs. the box-shaped, stock weren’t. If you insist on doing this, I’d suggest using an appropriate relay activated by the ignition and use the existing lighting circuits and fuses to route the power. Sometimes people do this (minus the ignition link) with the older light switches because they seem to a bit marginally designed for the job. I think there was an article in the Alfa Owner sometime in the past few years on just how to do this.