Light fixture (5)
I believe the answer is:
match
This clue is a double definition.
'light' is the first definition.
(match is a kind of light)
'fixture' is the second definition.
(thesaurus)
(Other definitions for match that I've seen before include "Lighter; contest" , "Formal contest - game" , "Partnership" , "Stick in a box?" , "Contest; pair" .)