@David Jonsson
I do not pretend to know the laws of Wisconsin or provide legal advice, but a couple of things:
I'm not sure how this thread became a discussion of the license requirements for wholesaling. Wholesaling is simply obtaining interest in real property as a principal and selling that interest as a principal. In Utah (or anywhere?), you do not need a license to buy or sell interest in real property. Was there anything in the letter to suggest that wholesaling was a concern?
Because they asked specifically, I would be more concerned about the use of "partner" in your marketing letter. If you do have a partner, you may be providing real estate services for a third party or have securities issues. If you do not have a partner, you may be misrepresenting your intentions.
@Bill Gulley suggested saying it was your dad who you may consult with or borrow from. You may tell them that you include it in the letter so sellers don't get freaked out when you show up with someone else or something to that effect.
I'd start by being honest with them and perhaps a bit dumb explaining that you are an investor and the partner is your father. If it's a problem, you will quit using the term "partner" immediately.
From my experience here, professional licensing is harder on licenses (including inactive) than non-licensed individuals doing the same thing like acting as contractors etc.
Maybe they tell you that if you're going to continue this, you need to activate your license.
Good luck and keep us posted.
Wm