Trivia: "The Box" was based on a short horror story entitled "Button Button" by prolific and legendary sci-fi author Richard Matheson. Matheson's original story was first published in a 1970 issue of Playboy Magazine. He adapted his own story for the screen in a 1985 episode of the new "Twilight Zone" TV series, but it was significantly rewritten after he submitted it. Matheson was so angered by the Twilight Zone rewrite that he refused to allow his real name in the episode credits and instead used his pseudonym, "Logan Swanson."
Trivia: Because she had to spend a good amount of time lying down with her eyes closed, Christina Ricci fell asleep while filming the funeral scene, eventually being awakened by Liam Neeson.
Trivia: Annette Bening plays Naomi Watts' mother in the movie, even though in real life she's only 10 years older than Watts.