Alobates pennsylvanica, called the "False Mealworm Beetle". I found under the bark of a fallen dead sweetgum in my yard. (I had let the tree rot in place, since it was in no danger of falling on the house. It was a great woodpecker tree for about a year.) Length about 18 mm.EOL has this as
Alobates pensylvanicus (one "n", masculine gender), as well as
Alobates pennsylvanica (two "n's", feminine gender), and I'm not sure which one is correct--these spelling/gender variants are pesky!