In 1855, a group gathered in a rented house on Campo Lane in Sheffield. They were there to investigate a haunting, but one of the group would soon be dead...

Sources and further reading:

"Scared to Death", David Clarke, Fortean Times 284, p. 34 - 39

Wikipedia - Spring-Heeled Jack

'Scared To Death', Scientific American: https://www.scientificamerican.com/article/scared-to-death-heart-attack/

'Spring Heeled-Jack and the Terrified Child', Mike Dash's blog: http://blogs.forteana.org/node/105