Many people in Thailand have a strong belief in ghosts and spirits and wear amulets for protection, good fortune, and to keep bad spirits away.

Ghosts are believed to be found, among other places, in certain trees, burial grounds near Buddhist temples, as well as some houses, especially abandoned houses. There are different categories of ghosts. Certain ghosts dwelling in mountains and forests are generally known as Phi Khao (ผีเขา) and Phi Pa (ผีป่า). Geographic locations such as the Phi Pan Nam Range (ทิวเขาผีปันน้ำ), "the mountain range that the spirits use to divide the waters", and Phae Mueang Phi (แพะเมืองผี) are named after the ancient ghosts believed to dwell in the places. Female ghosts or fairies related to trees such as Nang Ta-khian and Nang Thani are known generically as Nang Mai (นางไม้ "Lady of the Tree").