The Mysterious Class Season 1 Episode 4
귀신이 척 하면... 귀신한테 혼나. (If You Pretend to be the Ghost ... The Ghost Itself Will Punish You.)
Desperate to satisfy his online followers, Jung-hwan resorts to secretly fabricating fake paranormal events and filming his classmates' reactions to them. Jae-hyuk unexpectedly discovers the ghost's identity.