What action could erroneously bring someone back as a vampire according to folklore?

The idea that cutting oneself in a churchyard could erroneously bring someone back as a vampire is rooted in folklore that associates blood and sacred spaces with the potential for supernatural occurrences. In many traditions, blood is seen as a vital essence, and when it is spilled, especially in a location that is considered holy, such as a churchyard, it is thought to create a connection to the spirit world. This connection could hypothetically disturb the resting place of the deceased and bring them back as a vampire, a creature often linked to the taboo of infecting the living and breaking the boundaries between life and death.

Each of the other actions listed lacks the same folkloric basis. Planting a tree near a grave traditionally symbolizes life and renewal rather than a means to resurrect the dead. Screaming at a tombstone does not have an established link to creating a vampire, as it does not interfere with the grave in a significant way according to vampire lore. Lighting a candle on a birthday is typically a gesture meant to honor the deceased rather than invoking a return from the dead. Thus, the understanding of blood sacrifice in sacred spaces reinforces why the act of cutting oneself could be viewed as a trigger for such an unnatural resurrection as that of a vampire.