This looks like a male Metaltella simoni (Desidae) to me, but I am not sure if they have been documented in Michigan yet. (BugGuide has one from Minnesota.)
Hi, I agree with Amaurobiidae as being most likely, it looks like it might be a male Amaurobius ferox but the details are too out of focus for me to be sure of it. The Metaltella simoni on BugGuide that was documented from Minnesota was collected in a green house, so that would be one to consider if the basement is being used to store things that were shipped in from out of state.
This looks like a male Metaltella simoni (Desidae) to me, but I am not sure if they have been documented in Michigan yet. (BugGuide has one from Minnesota.)
Otherwise likely a male Amaurobiidae.
Hi, I agree with Amaurobiidae as being most likely, it looks like it might be a male Amaurobius ferox but the details are too out of focus for me to be sure of it. The Metaltella simoni on BugGuide that was documented from Minnesota was collected in a green house, so that would be one to consider if the basement is being used to store things that were shipped in from out of state.