I found this jar 'thing', hand-painted and sealed. It looks like it is a memorial jar in which you might store the ashes of "Whiskers" (a cat, presumably), but it is empty. It does not open. Perhaps it holds Whiskers' ghost...?
Somewhat related, I also found this ADORABLE little mouse figurine. At first I thought that it was the mouse from "If You Give A Mouse A Cookie", but after I got home and looked it up and that mouse is slightly different.