Supernatural - The Mentalists

Dean is by himself investigating a some strange murders involving Psychics in Lily Dale, New York.  He goes there to investigate (wearing his FBI getup) and sees Sam sitting at a diner (also in FBI getup).  They are both investigating the same murders and so Sam reluctantly agrees to work together on the case.

There are two deaths, one the woman was brained by her crystal ball and the other impaled by the ouja board planchette.  First they think it's a necklace that the first medium was wearing that was handed down to the second medium.  But when they get it from a pawn shop guy they find out it was made in China.  They visit the granddaughter (Melanie) of the second victim.  They find out that she had a premonition of her death.  One of Melanie's friend also gets a vision and so she calls Sam & Dean.  They see on a video that the ghost that gave them premonitions was an old Psychic named Kate Fox.  They visit the local museum where a guy working there tells Dean that Hellen wants him to know that he needs to talk things out with Sam or she'll come from beyond the grave and kick his ass.  So he talks things out with Sam.  Then they dig up Kate's grave and salt and burn the bones.

But this does not stop the ghost because Kate was just warning people of their deaths and it's actually the ghost of her sister Margaret that is killing people.  So Dean stays with Melanie while Sam goes and talks to the Pawn Shop guy since they figure out it was him that was binding Margaret.  Sam ends up shooting him and finds her bones and salts and burns them.  Sam & Dean save the day and they are hunting together again.