Essay: “Bullion”, William Hope Hodgson, 1911.
Like some Carnacki tales, this story starts out with what seems to be a supernatural event and ends with an entirely natural crime being exposed.
The narrator of this story is a second mate on a ship whose captain died on the voyage to Melbourne.
The new captain thinks his cabin is haunted since he hears whispering at night, and he switches cabins with the second mate.
The ship is carrying gold, and the whispering is the work of a gang of thieves who are slowly replacing the cases of gold bullion with dummy cases filled with lead.
The first captain probably died of long term exposure to the narcotic fumes the thieves put in the hold with the gold so the narrator and the captain, sleeping there to guard the gold because they suspect something is up, won’t wake up during the substitutions.
Naturally the plot is foiled.