Hello Chris,
As you know, a person with schizophrenia can have visual hallucinations, not as common as auditory ones, though.
Another time this happens [and it happened with me] was in that moment between sleep and waking, or being awake and sleeping, which is called hypnogogic. I saw a smoky red figure flash out in front of my eyes.
Regret I, too, can't remember whose SharePost it was.
Regards,
cb