I've been seeing and hearing things. Should I be concerned?

To be clear I'm not actually diagnosed with Schizophrenia and I'm not necessarily trying to self-diagnose either because I don't wanna be cringey, but lately I've been noticing some things that make me worry I might be developing it or be somewhere on the spectrum judging by my research and what I've noticed. It might be nothing, but It could also not be and I honestly don't know. Lemme just quickly go over what I'm talking about:

I used to work at a local Dollar Tree as a stocker, and when they first hired me they had me work early mornings starting at 5 AM. I don't have a car or a licence so that meant waking up around 3 AM and walking the 2.5 miles to work in the cold and dark mornings. For the first few weeks everything seemed normal, but maybe after a month or two of working there some weird things started happening. I began to notice vague shadowy figures out of the corner of my eye that would dart across the ends aisles or just be there for a second while I was working. I brushed it off the first few times, but it just kept happening several times every shift. One time one of them randomly flew over my left shoulder, which scared me enough to make me jump. Before that point I was able to just kinda ignore it thinking I was just tweaking a bit, but that time pretty much confirmed that I was actually seeing things. I mean it actually visibly affected me and made me move, which was just totally bizarre.

During this time I mostly just saw the figures, but one time on the way to work I clearly heard the crosswalk "wait" sound. I was just walking down a dark neighborhood street and there it was. Nobody really believed me or thought anything of it when I told them, but I know I heard it. I wasn't anywhere near a crosswalk and it echoed around me like the crosswalk voice man was there with me in spirit telling me to wait. I actually heard it a few times because it echoed around me a bit. I kinda rambled but I swear I heard it and I'm not making any of this up. Eventually though my boss moved my shift forward three hours to start at 8 AM and the symptoms went away, which leads me to believe that this was at least in part caused by sleep deprivation. I don't think that's the whole story though because it went on for a good while and I usually got at least 5-6 hours a night, which definitely isn't 8-9 but I think it should've been enough for 18 yo me to function okay.

I have other stories besides this one that happened before and after, but I feel like it's the most telling out of all of them. To gloss over some others, I've:

- Experienced what I think were derealization episodes at work on two separate occasions

- Heard the word "hey" randomly while walking alone at night when I knew for certain there was nobody around

- Been startled while trying to fall asleep by a blurry vision of a hand holding some black object and a sound similar to a "boo", which just happened recently

There's other things but visually and auditorily at least that's my experience. This post is already very long. Is this a cause for concern? Should I see someone? I would appreciate any thoughts.

I’ve known people with bipolar who have mild symptoms that are brought on by lack of sleep.

I have had about 5 hypnopompic hallucinations in my life (when waking up), and only one of them seemed real enough to scare the s#$% out of me, and was definitely not human by appearance.

Sleep insomnia can make normal people psychotic and prone to 'seeing things'. There were experiments done on 'normal/non-psychotics' under conditions of pure isolation and sleep deprivation, which led them to hallucinate and lose sense of perception. I have heard (I think it was David Eagleman) that the reason people dream at night is because that lets daytime-active mammals keep their visual cortex in use 24/7, and therefore not in competition with the other senses that would compete for brain growth while asleep. For people with abnormal conditions, like schizophrenia, I would say sleep is the number 1 factor impacting a 'normal healthy' person (meaning without substance abuse/addiction complications).

Shadows and low light conditions are the main stage for any illusion of the mind, with the whole 'we were designed to be watchful of tigers in the jungle' (rather safe>than sorry) metaphor.

I am convinced that auditory events are driven by suppressed stress and anxiety. Social circumstances govern internal thought processes.
Example: If you lived in the setting of 1984, then you would probably vent incoherent subconscious stress in the form of auditory hallucinations.
In your case, a xyz occurrence (job manager whining) can become a stressor with automatic responses in the subconscious.
And that might be vented when work ends or begins, in conjunction with a break from a routine/repetitive pattern.
I am guessing here, but this gives you an idea of what to ask or research about.