Like, weird stuff really did happen that was testified by multiple people that has no rational explanation whatsoever.
Group hysteria and delusion. The accusers were adolescent girls, many of them survivors of King Philip's War (1675-1678). They were near the bottom of Salem's social structure, and discovered that accusing people of witchcraft won them popular influence and a degree of power.
And read a little history: no one was burned at Salem. 19 people were hanged (13 women, 6 men), one man was pressed to death, and up to 20 accused people died in prison, including infants actually born in prison.