While he struggled along on an income of 150 talers at most and endured poor living conditions, Ranft conducted research on vampirism.
His sons Michael Gebhard and Christian Solomon Ranft were also pastors in Großstechau or Rückersdorf.
Ranft recounts cases reported from Germany of dead persons devouring the linen and everything else that was in reach of their mouths, and claims that people who happened to be nearby would hear sounds as if of pigs growling and grunting.
A particular case he mentions is that of Heinrich, Count of Salm, who after being declared dead was put in his grave, in the churchyard of the Abbey of Haute-Seille, while he was still alive.
Witnesses claimed that they heard loud cries during the night at the place he was buried, and the next day they opened his tomb, disinterred him and discovered that he had gnawed the flesh of his arms.