Is this a crayfish hole? or wasp nest? I'm suspicious that it might be crayfish, which I'd think was insane (I still kind of do), if I hadn't found a dead one around my house earlier this summer. Is that definitely what it is, or do I have to worry it might be wasps? I'm located in Michigan. !enter image description here

It is indeed a crayfish hole (sometimes referred to as a "snakehole" in Michigan, even though it is not from a snake), albeit it has eroded from weather. If you have one in your yard, you likely have dozens, and they will range in their appearance due to soil and weather conditions.

Example 1 and Example 2.