The story of Ernie is inspired by the ghost that is said to haunt the New London Ledge lighthouse, the location that inspired this film, but was too impractical to shoot on.
The lighthouse light is actually quite dim in real life and was augmented for filming both with film lights and CGI.
The lighthouse was accessed by boat and all of the equipment had to be carried up a ladder.
Branden and Erica are named after the Director of Photography and Line Producer of Stalker's Prey (2017) and Stalker's Prey II (2020), neither of whom were able to work on this film.
The keeper's house was actually located on a city street, not an island.