At top of descent to Los Angeles, the cabin crew of the Boeing 747 aircraft reported smoke and fumes emanating from the cabin ceiling located in the vicinity of the rear right side (R5) emergency exit door. Smouldering paper tissues were found in an overhead light fitting. Cabin crew removed the tissues and discharged a fire extinguisher onto the light fitting, tissues, and surrounding area. The cabin crew remained in the vicinity and monitored the area until passengers disembarked at Los Angeles.
The company reported that the light fitting is a "night light" and is always "on". The light has a blue plastic cover that should always be in place, but was not fitted on this occasion.
The investigation was unable to determine why, or by whom, the tissues were placed in the light fitting.