In an old pagan cemetery in which the dead of a local village are interred to this day, there are bodies buried from an age long before any of the local mundanes can remember. Though the local parish priest has consecrated the graveyard for the church, the hallowing did not work properly for unknown reasons. Over time, the fat of corpses buried here, unless given a church burial, transforms into a pale gray corpse wax.
There is wax enough on each body to harvest for 2 pawns of Corpus vis. Long after burial, the corpses decay to skeletons, and the vis is no longer harvestable.
However, the local mundanes will not look kindly upon those who would steal into the graveyard in the dead of night and dig up the bodies of their ancestors. They may, at first, blame it on ghouls or some other supernatural menace, but if such things begin to happen regularly, or if interlopers are spotted in the graveyard, they will investigate and even post watchmen to keep an eye on the cemetery. Certainly, any local stronghold of "witches" would immediately fall under suspicion, since the local parish priest suspects already that such persons are trafficking with Infernal powers.