Alone (2007)
Alone (, or Fad, literally "twin") is a 2007 Thai horror film directed by Banjong Pisanthanakun and Parkpoom Wongpoom, a duo whose debut film, Shutter, was a box-office smash in Thailand and other Asian countries. Alone stars Thai-German pop singer Marsha Wattanapanich in her first film role in 15 years.'
More at Wikipedia.