Can anyone identify this pin?

Hello! I am not sure if this is the right place to post this, but I was wondering if anyone could help me identify this pin? I found it deep in an air vent in the floor of my home, so it must have belonged to someone who lived here before. I was just curious, because the house was built around 1920 so I wondered if it might be old? It is very small, just 1/2 inch across. Does anyone know what it could be or what the symbol means? I tried to google but couldn't find much. Thank you for your help!