Stumped museum curator — can you help?

So, it was natural my cousin sent someone to me when they found something odd while removing an old chimney in an old house in Nebraska. “What is it?” they asked. It was a little card with some words and letters and numbers printed on it. The longer I looked, the less sense it made. I had no idea. In fact, it’s been a few years since they asked, and I still have no idea.

Running across this photo again I’d kept for reference, I got back in touch with the finder and asked if he had any answers — Still no.

I’d lost any details I’d had, so he kindly sent me more info:
The card is 2″ wide, 3.5″ tall and totally blank on the back. Much smaller than I assumed it would be.

With an ornamental border it reads:

a 10
G. Robbins
Miss Harrison,
J. F. Hull
Gracie Battis
M

And that’s all I know about it. Do you have any ideas?

Originally published at https://benjaminlclark.com on March 13, 2020.