Hi Bluey Moon,
I don't personally have unusual or random thoughts of this nature, but I know that this can be experienced by those with Obsessive Compulsive Disorder (OCD), which is an anxiety disorder. I have OCD, but my problems pertain to a fear of germs and involve compulsions such as excessive hand washing. Some people with OCD have unwanted and horrific thoughts, often of a violent or sexual nature. These thoughts are not acted upon, but cause the individual significant distress, as the sufferer can start to feel as though they are a horrible person for having these thoughts. This is not the case, as the thoughts are unwanted and the result of a mental health condition they can't truly control.
Because you only have these thoughts occasionally, I highly doubt you have OCD. An important question to ask is: do these thoughts cause you significant distress and interfere with your life? If not, it seems you are just having what you said - bizarre and random thoughts - which happens to many people from time to time. I am not a professional though; so if in doubt seek help. Have you been diagnosed with an anxiety condition before, by the way?
If you have other symptoms or concerns, you could enquire next time you visit your GP (or make an appointment sooner if needed).
Beyond blue have resources about anxiety, so have a read. Here is the link to info on this site about OCD:
https://www.beyondblue.org.au/the-facts/anxiety/types-of-anxiety/ocd
Best wishes,
SM
