Love After Death (1968)

During a cataleptic fit, Montel is buried alive--a burial plotted by his greedy wife Sofia with several men, including her lover, Montel's doctor. Exiting his grave, Montel goes on a sexual rampage. When the conspirators engage in gunplay at an abandoned castle, Montel arrives to stab the doctor and strangle Sofia, followed by the revelation that he is actually dead.