I have a very old skeleton key that belonged to my grandmother. I found the key lying around shorty after she passed away. I tried every lock in the house and the key did not open one door. I decided to keep it. It sits on my bureau at the feet of a statue of Naga Kanya.
Some folklore legends says that if you carry an extra key on your key ring you will always have the answers. ...I wonder if this is what that lock-less key was to my grandmother - symbolic of her intuition and always knowing the way.