Hell-ephone

The story of a prank gone horribly wrong. A group of college students, led by "The Circuit Maker", a Svengali-like professor, make prank calls to funeral homes. After intently researching the obituaries, they try and convince whoever answers the call that they are the deceased calling from the great beyond. As the prank gets larger than life, gaining national attention, they attempt the biggest prank ever: they will 'Hell-ephone' the funeral of a recently executed serial killer, known as "The Sea-Monster". When the Sea-Monster's mother drops dead after taking the call, the kids start showing up dead. Mike Stone, the leading detective on the Sea-Monster case, is convinced that the Sea-Monster has returned from the grave to avenge his mother's death. The rest of the police force, however, doesn't buy that theory. Now cavorting with the ultimate evil on the other side; has the Sea-Monster been given to power to come back and continue the reign of terror that was interrupted for ten years while he sat on Death Row? - IMDb