I'll add what I originally said. It was something like: My vote is for Carolina wren. They like all different places around here. One time we weren't able to use our table saw because we had thrown a tarp over it, and there was a nest of babies under the tarp.

Then I wanted to bring in some pots that I had made from the barn, but I put them in a container on the porch until I could wash them. I'll post the pic of what I found one day. One thing you have to be careful of is to not check on these nests very often, or touch them. Predators can smell your scent and it might lead them to the nest. I really love Carolina wrens. They are feisty little guys (and gals). I have them here year round.