Ship's radio operator (6)
I believe the answer is:
sparks
'ship's radio operator' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for sparks that I've seen before include "Flashes from electrical discharge" , "Electrical discharges" , "They fly from fire" , "Fiery particles for informal electrician" , "Momentary flashes of light" .)