The tale of Mae Nak Phra Khanong is known to most Thai people. It goes back to the reign of King Rama IV (King Mongkut). Mae Nak and her husband Mak lived by the Phra Khanong waterway in Bangkok, where her shrine is now located.
While Mak is off at war and severely injured in the process, bot Nak and her child she is carrying die during childbirth. However, when Mak eventually comes home, Nak is there with her new child, as if nothing has happened. Neighbors, who know what happened, and try to tell the husband, are met with a dismal faith.
The story goes, that when Nak was preparing a meal with Nam Phrik, a lime fell down through a crack in the floor. It fell down to the ground below the house (which traditionally is elevated to be safe from floods). Nak, as a ghost, extended her arm to pick up the lemon, which was seen by her terrified husband. He henceforth tries to flee the house, and runs away at night.
Nak does not let go and pursues her husband. Mak is almost caught but manages to conceal himself behind a bush. Ghost are afraid of the sticky Blumea leaves. Mak then finds shelter in the temple at Wat Mahabut, where Nak can not enter the sacred site.
She (or rather her ghost) then terrorizes the people of Phra Khanong, who she blames for helping her husband leave. The help of an exorcist is required. The exorcist manages to bind the ghost and confines Nak to an earthen jar, which is throws away in the canal.
The jar however is found by unsuspecting people, and unwittingly the ghost is freed.
Eventually the ghost can be subdued again by a powerful monk (there are different storylines as how this happened).
The Mae Nak story is very popular, and is seen as an example of true love and devotion. Numerous movies have been made about it, invariably successful.
The Mae Nak shrine (she is now rather called Yaa Nak, or grandmother Nak) is located off Soi 7 and Onnuj road (off Sukhumvit Road). Walking there from the Onnuj skytrain station, will take about 20 minutes, but you can take a Songthaew ride (if you know where about to get off, soi 7 is at a major bend of the road to the right).