seniorjudge said:
A: Yes. You will have to file in Wisconsin.
Sorry, but NOT true.
You can file your claim in California. When the defendant is served with your lawsuit, he then has the right to file a motion to dismiss, claiming that the California courts have no jurisdiction. If the court agrees, they will dismiss your case and you will have to re-file in his state. However, if he doesn't challenge the venue or if you are able to show the court that California does have relevance.... then the case would be heard there.
Of course, if you get a California judgment against him, you would have to then domesticate that case to his home state... but that is a fairly simple process and likely wouldn't even require a visit there.