We suspect it was the previous owner's young daughter and she intended the wire to hold in the braid. I don't think she meant any harm, but probably was afraid to tell her mother what she'd done when she couldn't get the wire back out - so she just left it. Mom wasn't particularly observant when it came to Dancer. Didn't even know she could single-foot!
Oy yoy yoy! Gotta love kids...how would you not notice a wire in there, though? Anyhoo, glad she's in a better home now!