Found at a new site that had house 1890s. Says Murray Seal I think and USMC. No clue what it is. I'm pretty sure it's not a dog tag . Maybe a zipper was on it?
It’s the main part of a “Murray Seal”, patented in 1932 as a tamper-evident lock for electrical meters and such.
"The invention aims to provide a seal of the “padlock” type for use in sealing electrical instrument boxes and the like in which a hasp has hooked ends which are thrust into the seal or casing and cannot be withdrawn without destroying or injuring the seal in some manner which will be apparent to the inspector for the electrical company."