Can my spouse remove my name from our joint savings account without my permission and/or knowledge, in WI?

Yes he can, and he will do more of this as long as you wait for him to make the first move. Your best bet is to get to a WI family attorney and file a motion in court (called a pendente lite motion) to prevent him from doing this to other assets. He can also cancel all insurance and benefits while you sit at home waiting for him to file for divorce.You might find my legal guide on selecting and hiring a lawyer helpful.
You might find my legal guide on Is it Legal? Is it Illegal? helpful.
You might find my legal guide on the understanding the different court systems helpful.
You might find my legal guide on legal terms used in litigation helpful.
(Even if you are not filing a lawsuit this information can be useful).

You might find Gabriel Cheong’s legal guide on the do and don’t of finances after a divorce helpful.
You might find my legal guide on divorce in general and in NJ helpful.
(Much of this information is valid for unmarrieds who have children together).

LEGAL DISCLAIMER
Mr. Sarno is licensed to practice law in NJ and NY. His response here is not legal advice and does not create an attorney/ client relationship. The response is in the form of legal education and is intended to provide general information about the matter in question. Many times the questioner may leave out details which would make the reply unsuitable. Mr. Sarno strongly advises the questioner to confer with an attorney in their own state to acquire more information.

should be able to remove your name, but certainly can empty it out as a joint shareholder.