A perception of seeing or hearing something that isn't there but lacks an actual external stimulus is called what?

The correct term for a perception of seeing or hearing something that isn't there, without an actual external stimulus, is hallucination. Hallucinations can occur in various contexts, including mental health disorders, neurological conditions, or as a result of substance use. Unlike illusions, which are distortions of real external stimuli, hallucinations are entirely fabricated experiences that do not have a corresponding external source. This distinction is crucial in understanding the nature of perceptual disturbances.

Apathy refers to a lack of interest or emotion, and confusion pertains to an impaired understanding or awareness of one's surroundings or situation. Neither of these terms accurately describes the subjective experience of perceiving something that is not present. Thus, hallucination is the most appropriate and specific term in this context.