Another option for you might be to contact the attorney for the plaintiff and let him know that the process server served you, but that you are not Amika and that you do not know who she is. If that fails, showing up on the court date would probably be a good idea, just to get rid of the issue for you. Of course, if you just forget about it, nothing should ever happen to you (unless they try to serve Amika there again!)
You should try a Hearing in Aid of Execution or similar action in WI. Basically, you call the debtor into court to testify about his assets. You can find out if he is paid as a wage earner (which you can garnish), where he banks (which you can levy), and his nonexempt assets. Depending on the size of the debt, you may consider hiring a collections attorney to help.
They should show the debt as discharged in bankruptcy. You should do a couple of things at this point - first, contact your bankruptcy attorney. Part of his/her job is to make sure that your creditors are/were aware of your bankruptcy and that the debt is discharged. Second, contact the credit reporting agencies to dispute the debt - at the very least, then it will show up on your credit reports as disputed. One thing you might consider if the company does not remove the amount owed is to...
The garnishment is not "automatically" in effect when you start your new job. As the others stated, they will need to find out that you have a job and where it is before they can/will garnish you. However, as soon as they find out that you are working or have money in your bank account, they will garnish you asap.