A major hit in Indonesia and is rebooted in 2017 by the same directors (this one has less favorable reviews than the original).
Jelangkung has the same principle with an Oija board. They are used to contact spirits, and they'd usually spell out the answers given to them.
This is not the first use of jailangkung in Indonesian cinema. In 1975, there was another movie with jailangkung themes titled "Penghuni Bangunan Tua" or loosely-translated to "The Old Building Resident" directed by M. Shariefudin.
Was actually made to be aired on TransTV (which wasn't broadcast nationally until 2002), but producer Erwin Arnada advised on giving it a full theatrical release. Even without sponsor or commercials, the movie became very successful in independent cinemas until it got a nation-wide release in the middle of December 2001 where it became the movie with the highest numbers of theatergoers until now.
The song that is constantly whistled by the character Gembol is actually the Scooby-Doo theme song.