Spooky true story about a dictators haunted tomb. https://www.catholicworldreport.com/2020/09/05/st-teresa-of-calcutta-and-the-dictators-tomb/
it doesn't involve christians but I know a similar story: pol pot's tomb in cambodia is now a spot where people go to pray for good luck in the lottery. I think its just a small grave with no markings of any kind, not even a stone. (which is strange, buddhists usually cremate and dissipate ashes of corpse)