Reddit user dragonxp1 recently stumbled across a joke book from 1940 entitled, 10,000 Jokes, Toasts, and Stories, and found this Hitler joke (#5524):
Hitler went to a fortuneteller and asked her, “On what day will I die?” The seeress assured him that he would die on a Jewish holiday. “Why are you so sure of that?” demanded Hitler.
“Any day,” she replied, “on which you die will be a Jewish holiday.”
[via draonxp1 on reddit]