Ghost Whisperer (2005)

S02E15 Mean Ghost

Melinda visits Grandview High to deliver a talk about her professional journey. During her time there, she witnesses a group of cheerleaders facing cruel and spiteful incidents right before their upcoming semi-finals. Investigating further, Melinda uncovers that a deceased cheerleader is trapped in the physical realm and learns that a mysterious force has been targeting the cheer squad with dark magic.