Alien

Oh this is a fun one.
The way it was introduced to me was that the item was a tiny little doll.
The doll would go about “Tagging” people. (Hidden in secret from person to person).

Eventually when it came to a certain time, such as at lunch times, we would sing a song to initiate the activity and find said doll and see who the current “ Tagged” person was.

If you were the person holding the doll, then you would have to perform a task such as sing a song for the group.

You could use a toy plane for example if you didn’t want to use a doll and say that if you were the one in possession of the plane, you were “ In Transit”. If you were caught “In transit” at Lunch, then you would need to perform a task.

Set it up, with a few options of tasks to give a choice of activities to anyone who might end up “Tagged or In Transit” at the start of the week on a camp for example and let the game run for the duration.