Okay, so here's where I'm at. (I'll try to post a pic or two.)
The noise seems to be occurring when the tire spins and hits a certain spot. Like it's catching on something. The noise stops immediately as soon as I apply the brake. Would be really nice if there is just a chunk of one of those nuts that are all over the ground here stuck in that little space behind the brake disc. I can see some scratches on the edge of the disc where it may have rubbed against something. I'm still hoping for the easy fix, lol. Can I maybe run a pipe cleaner or some kind of flexible brush or something through that gap to see if anything is stuck there without harming anything? I believe it is open at the bottom too because I can see some light from the flashlight below it when I shine it down in there where the arrows are in the 2nd pic. Lemme know what y'all think.