I could probably provide the death certificates or some form of relative match.
If you are the next of kin, you can... you'll have to gather up all the other relatives, though...
This is not legal advice. I am not your lawyer. You are not my client. You cannot rely on my response to your question. My response to your question is probably worth exactly what you paid for it. You don't get to sue me for anything. If you'd like to sue me, well you have to hire me first.
Estate Planning Attorney
You should be able to claim the property. However, that does not make it yours. It needs to be distributed as provided in their Wills, or if no Will, to their heirs at law. I would use the Wisconsin Transferby Affidavit form if the value of the unclaimed property is less than $50,000.