If you work at a company with more than a 100 or so employees you probably get an email every couple weeks about a phone or some other item being found in the breakroom/restroom/conference room, often with a note saying to email or call with a description of what you’re missing so that can confirm it’s yours.
All very practical.
Maybe not a lot of fun if you’re the keeper of the lost items. Maybe not a lot of fun for you, if you see it as a distraction (and assuming you haven’t lost anything).
Me, I see it as a chance for some fun!
For example, recently someone left a ring in the break room. I go to Google images, find a picture of a toe ring on a toe with some nice polish, paste that into a reply with a note that I’m so glad they found it and hit send. I’m kind enough to not ‘reply all’, though some rainy day I’ll probably have to give that a try too.
Lots of ways to be over the top without crossing any HR lines. Be creative, it’s good for you!