The flame in the lamp lit before Hindu deities is the most auspicious form of Agni. The popular belief in Hindu tradition is that the lamp lit before a Hindu God or sacred place should go out only when the oil in it is completely used up. If the lamp goes out before the oil is used up, it is termed inauspicious. Elders say that it will bring bad luck and calamity.
The main reason for this belief is that Goddess Lakshmi resides in the flame. Interrupting Her stay is inviting bad luck. Thus it is suggested that the flame on a lamp is an indication of fortune.
Some elders are of the view that as the lamp lit before a Hindu deity is something very holy, an abrupt end to it suggests dislike or displeasure of the deity. People in such homes might be unclean or there will be constant fights in the family. Lamps flutter and are soon put out in homes that encourage evil thoughts.
It is also believed that Goddess Lakshmi resides in homes that are clean and surroundings that are neat. The lamp going out even when there is enough oil is Goddess Lakshmi walking out of unclean home and Alakshmi, the goddess of misfortune, taking her place.
Lastly, a lamp going out on its own when there oil and black smoke and bad smell emitted suggests that people in the family are disinterested in spiritual activities. The lighting of the lamp is done for namesake. It is only natural that such families face constant troubles and bad luck.