Widows Mites were small bronze coins with an anchor / "wheel of eight" (spokes) of Jannaeus Alexander from about 200 BC. The wheel of eight design, I understand was used by early Christians three hundred years later, as a safe sign of recognition, as they were under persecution. Think of a love token with three initials one over the other. Chi, Rho, Theta in Greek for Christ would make a rough "wheel of eight." They may have chalked that symbol on inconspicuous places of safe houses to communicate to others, about meeting places without letting the authorities know what was going on. They say during the depression that hobos had a similar symbol language, and would put symbols on mail box or fence posts about the quality of reception they got asking for a meal at the back door of each farmer's house, to let other travelers know whether to approach, not to bother, or run. Probably this is all a coincidence, but you never know. Your item looks ancient to me. Keep researching and you may find out it is something significant.