I just had the same problem..made a shim from the top of a plastic coffee lid and put it in front of the switch works fine..

 

I had a similar problem on my SB when I powder coated the front end. I snipped the tip off of the switch when I put my handlebar controls back on. Bought a Drag Specialties switch for $20 buck and replaced the broken one. Yes you have to solder the wires but it was no big deal. Soldered it and used shrink tubing, problem solved....

 

So I did the bend trick. I put a slight bend on the lever plunger piece end that touches the small switch button. It now works perfect. Thanks all for the help with this!