Ghost Whisperer Episode 4.09 Pieces of You

Melinda continues trying to reconnect with Jim who has inhabited Sam's body. She fears she may have gotten him haunted after he makes a wish at a wishing well, which is answered by a creepy young female ghost.

Unsure how the ghost died in the well, or why she was answering people wishes, Melinda and Eli begin their sleuthing, initially working under the assumption that the girl, Gretchen, was murdered, possibly by her own brother.

However, they soon discover that simple sibling rivalry was responsible for Gretchen's death. Escalating pranks between Gretchen and her brother had led her to make a wish at the well that he get his arm chopped off, and he discovered this wish. He set up a prank where it appeared that he had lost his arm, and racked with guilt, Gretchen had returned to the well to take back her wish, only to fall to her death. Not realizing it was a prank and still feeling guilty, she had then spent years in the well answering people's wishes. Once Melinda helps her reconnect with her brother she is able to find peace and cross over, but not before granting Sam's wish. He had wished that he could have a clue to who he was in his forgotten life, and Gretchen helps him discover that he had recently purchased an engagement ring for an unknown recipient.