Nuclear physicist here!

I agree with the general consensus in the comments. Alpha radiation from radium is easily stopped by a few centimeters of air, a sheet of paper, and even the dead layer of cells on the outside of your skin. So long as you don’t eat, inhale or inject the radium, you’ll be fine.

I wouldn’t keep it on your person for an extended period of time though - for example carrying it in your pocket every day, sleeping with it under your pillow, etc. Store it somewhere safe and not immediately next to your skin; the back of a drawer or on a shelf would be fine. Feel free to use it or show it to people from time to time. That’s a neat piece of history to have!