Best thing that ever happend to me was the neutral light switch went, so I didn't get it replaced, just left it. Now I have none of that false neutral, light coming on and off rubbish.
Mine's done this on several occasions. Just left it then it seems to sort itself out. Usually after bike has been standing. I think its the switch that needs reshimming, with different thickness washer.
I've seen these complaints before, but I think I've only replaced one neutral switch on my last two Ducatis; that's knocking on 90,000 miles now. Mine works perfectly. They do need setting up right, as doogalman says.
Can these switches be dismantled to improve their performance then because mine is completely random as to whether it works or not. Given up looking at it now.