At some point these popped up and I’ve been unable to disable them. They are tied to the models as newly created objects don’t have them (see the sphere next to them).
I’ve looked for a physics visualization option as that was the problem for most similar problems I could find, but I found nothing and from what I've found I don’t think it’s a setting anymore, or just in a different mode or something.
I’ve searched pretty much the entire properties window, though it’s possible that I’ve somehow missed it after five passes of everything.
I’ve noticed turning off the overlays turns the boxes off, but if I turn off the individual options and leave the overlays overall on, it’s still visible. It’s also visible regardless of what object is selected and the current mode (object, edit, sculpt, etc.).
I’m on Blender 2.93.1.