Gas lighting was nominated as word of the year yesterday by Mirrium-Webster.
When I look it up, the source of the term is nominated as a 1938 play by Patrick Hamilton and then popularised in subsequent movies.
BUT...
Coincidently I read The Amorous Dentist by Robert Travers ( ISBN 0 207 13523 1 ) yesterday. On pages 44 and 45, the author reports that Henry Louis Bertrand used the word gaslight written on a scrap of pasteboard to frighten his wife out of her wits during a self styled seance. Bertrand was a notorious murderer covicted in Sydney in 1866. His infamy persisted into the 20th Century.
Could the Bertrand case be the ultimate inspiration for the term gas lighting.