Hmmm...tough question about the nut. Aside from going to Ernie Ball, I wouldn't know where to start.
You should definitely get in touch with them about that. Earnie Ball is really good about their customer support, so you should be in good hands,
Terribly sorry for the late reply. It's been a busy week.
Before ordering a new switch, check the connections on both ends VERY thoroughly. Very little goes wrong with those switches, so when something DOES, it's generally a wire or soldering point that is the problem.
Again, be very thorough...these small problems can often elude your eyes at first glance. Switches are expensive, so it's worth taking several looks.
If all else fails, you'll have to buy the switch through Ernie Ball. Here's the link for all their contact information: Ernie Ball
If you're within the US, your best bet is going to be to give them a call. I can never remember which number or who to talk to, but they're always able to direct your call to the proper department. If you're out of the country, email Nathan Stiff (firstname.lastname@example.org). He should be able to assist you.
Good luck with the switch, and please let me know how things go.