High emotional arousal can be a contributing factor to hallucinations in both psychotic and non-psychotic individuals, but I think if what you're trying to emphasize is the emotional/situational genesis of hallucination the best fit might be hysterical hallucination.
In order to answer this question first we might define what is meant by hallucination. (Note: I'm setting aside chemically-induced hallucinations entirely.)
While there are a number of sub-classes of hallucinations (e.g. auditory, visual, tactile) the general definition has evolved to have what is, essentially, a three-criteria definition of a perception that occurs (1) without a stimulus, (2) with the 'full-force' of a real perception and (3) can not be voluntarily controlled. According to Prof. Dr. Gopal Chandra Kar and Dr. Samrat Kar's "Aetiology of Hallucinations: Review" in the Orissa Journal of Psychiatry:
Esquirol (1932) 's original definition ofHallucination as a 'perception without an object' Jasper, in 1965 defined hallucination as corporeal and tangible. Jasper also suggested the definition 'a false perception-which is not a sensory distortion or misinterpretation, but which occurs at the same time as real perception. In 1997, Cutting defmed hallucination as 'perception without an object (within a realistic philosophical framework) or as an appearance of an individual thing in the world without any corresponding material event'. In 1988, Janzarik defined hallucination without associating them with perception at all, as free running psychic content Working definition of hallucination: any percept-like experience which (a) occurs in the absence of an appropriate stimulus, (b) has the full force or impact of the corresponding actual (real) perception, and (c) is not amenable to direct and voluntarily control by the experimenter (slade and bental, 1988). Jasper first of all distinguished between true perception (true hallucination and mental images).
While both of your examples seem to have some relation to a psychiatric disorder (in the first you reference being 'driven mad' and, while I don't remember the exact moment to which you are referring in "One Flew Over the Cuckoo's Nest" the setting is pretty suggestive), there is some research that examines hallucination as non-pathological process- or, at least, that they can arise from external emotional stimuli.
The best fit for this sort of emotionally-induced hallucination would probably be the psychoanalytic theory which (quoting from the same paper as above):
...postulates 'Hallucination may be substitutes for patient's inability to deal with objective reality and may represent their inner whishes or fears.
Hallucination can be result of intense emotions, suggestion, disorder of sense organs, sensory deprivation and disorder of central nervour system (Hamilton, 1994).
Such emotionally-driven hallucinations may be referred to as hysterical hallucinations (though, by no means, does this term cover all hallucinations with any basis in emotion) which:
...have a sudden and dramatic onset, and that they are often precipitated by a profoundly upsetting situation or event.
