The case of Waryam Singh
v. Emperor (AIR 1926 Lah 554) is on:

IPC In Waryam Singh v. Emperor AIR 1926 Lah 554, a Division Bench, acting under Section 79 of the Indian Penal Code, held that an accused who killed a man with several blows from a stick was not liable under Section 302, Section 304 or Section 304A 'ibid' because he believed in good faith at the time of the attack that the object of his assault was not a living human being but a ghost or some object other than a living human being. The Division Bench made it clear that the ground for their opinion was that 'mens rea' or an intention to do wrong or to commit an offence did not exist in the case and that the object of culpable homicide could only be a living human being. (In this case appellant's wife along with her husband were taking a bath on grave of her child believing that they would get her son back. It was a dark night and villagers mistook husband to be a ghost and killed him).