Rep. Haley Stevens says Rep. Tom Tiffany has only one thing on his mind as he runs for governor of Wisconsin ... changing hunting laws so he can hunt wolves!!!

The Congresswoman from Michigan appeared on CNN Wednesday morning to discuss the Democratic primary for her neighboring state's gubernatorial election in an interview that quickly went off the rails ... when she started howling about Tiffany's alleged wolf hunting obsession.

Rep. Stevens says all of her interactions with Rep. Tiffany, the GOP nominee for Wisconsin governor, have taught her three things ... he's a nice guy, is deeply conservative and his big priority is wolves.

CNN host Pamela Brown didn't hesitate to follow up ... and Rep. Stevens said Rep. Tiffany's talked to her multiple about hunting wolves ... namely, getting laws changed to make it legal.

Turns out ... Rep. Tiffany actually co-sponsored a bill in Congress to remove the gray wolf from the federal Endangered Species List and give control over population management to state wildlife agencies.

So yes, it seems Rep. Tiffany has wolf hunting on the brain ... though it's unclear if he's as obsessed as Rep. Stevens claims he is.

We've reached out to Tiffany's office ... so far word no back.