Another idea would be using a steam generator to power the light and the keeper pushed the generator too hard and the boiler blew out.

example is the De Meritens Magneto Generator
The French De Meritens magneto generators worked with great steadiness , revolving at 600 rpm. A De Meritens magneto was installed at the Lizard lighthouse, in England, and was used from 1881 until May 1950.