I must be having a bout of dejavu. This looks just like a metal piece posted a few weeks back. I am getting old. Anyway, looks like a pipe hanger to me. But I am no expert. Good luck with it and thanks for posting.
Pretty cool find, IMO. I enjoy trapping and recognized this piece pretty fast. Fur trapping helped build this country.chain swivel. Use them on my trap chains to keep the chain from binding up