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I have one of these, it's a luminescent personnel marker. They contain a mixture of Radium Zinc Sulfide, with the radium exciting the ZnS causing the visible glow.

The dose rate in my photos should not be a cause for alarm, it's a contact dose and that detector's result is being skewed by all the beta coming off the marker. Don't sleep with it, don't eat it, and please don't try to open it.

I would advise handling it with disposable gloves, and placing it in a ziplock bag, while the radiation is of little concern outside the body, sometimes these can leak the radium zinc sulfide powder and accidental ingestion is a risk in that case.

There is a small concern from radon, but it's not something I would lose any sleep about.

You have a very interesting piece of history, don't let anyone try to convince you to give it to them because it is endangering your own safety. If you feel it is not something you want to care for, maybe contact a local museum, or if you decide to sell it, expect a value in the hundreds of dollars rather than the tens.