Green’s Dictionary of Slang

1. (US milit.) a radio operator.

1914		G.D. Chase ‘Navy Sl.’ in DN IV: ii 151: sparks, n. Wireless operator.
1921		N&Q 12 Ser. IX 384: Sparky. Nickname for a wireless operator.
1925		(con. WWI) Fraser & Gibbons Soldier and Sailor Words 266: Sparks: A wireless telegraphy operator.
1939		Howsley Argot: Dict. of Und. Sl.
1940		‘Argot of the Sea’ in AS XV:4 Dec. 451/1: sparks. The radio operator knows no other name than Sparks.
1953		G. Durrell Overloaded Ark 235: Sparks, the radio operator, was one of those who always came and talked to George [i.e. a caged baboon].
1958		L.F. Cooley Run For Home (1959) 6: I’m a radio operator, therefore I’m called ‘Sparks’.
1972		‘Hergé’ Tintin and the Land of Black Gold 10: Hey, Sparks! ... trying to call up Mars?
1981		G. Young Slow Boats to China (1983) 371: ‘Sparks here puts everything down to magic, don’t you, Mr Low?’ The radio officer smiled bashfully.
1984		(con. WW2) T. Jones Heart of Oak [ebook] We had a running commentary, in Obstinate, from a sparker who passed it on to a wardroom steward, who passed it on to ... anyway, in action, a destroyer is a network of jungle telegraphs.

2. (also spark) an electrician, usu. theatrical and film use.

1938		H. Borust In Plain Clothes 184: Scene shifters, ‘sparks’ (light men), wardrobe-keepers [OED].
1971		Guardian 24 Sept. 12/4: I went to Manchester as a spark’s mate – an electrician’s mate.
1984		A. Sayle Train to Hell 48: The lighting men, known as sparks, had got on the train.
2000		I. Rankin Set in Darkness 262: A sparky positioning a ladder under some ceiling cables.
2003		McGill Reed Dict. of N.Z. Sl. 196: sparkie An electrician ANZ.
2007		L. Redhead Cherry Pie [ebook] ‘Shouldn’t have rushed into it, like the sparky job’.
2010		Sun. Times 19 Dec. 15/6: ‘Problems with the brickie,’ ‘the sparkie has flu’ and dozens of similar excuses.
2021		P. Papathanasiou Stoning 80: ‘[W]elders, plumbers, sparkies, chippies – that kinda actually useful stuff’.