Magic Forums

My neighbours are North African and practice some elements of witchcraft from this region. We have a history of not getting on (especially after they threw rocks at my cat). For the most part I ignore them but I have just discovered that they have thrown something strange onto my terrace. It's a cost hanger that has had the hook part removed and it's then been twisted into a triangular/ pyramid sort of shape.
Before I attempt to remove it tonight can anyone tell me what it is? This has been very carefully done so it's not some random object.