What jobs could one get after studying parapsychology or demonology?
Well, you'll meet a lot of parapsychologists here if you keep your question open long enough.
Many are 'debunkers' - so they learn about things beyond psychology only in order to explain that there are no things beyond psychology.
In my country, there is an obscure university which gives diplomas in the field of parapsychology after 3 or 4 years of studying, but the graduates are most often considered some sort of freaks and no 'serious' company would hire such 'specialists'.
Being pretty much an uncharted territory - there are theories over theories and documented phenomena, but still rejected by the 'scientific' societies, being a parapsychologist could be a challenging job.
As for demonology, there already is a classification - search for 'Book of Enoch' - and, since demons are not something that are being born every day, I guess you could teach about them in the field of classic mythology.
Of course, if you mean an active demonologist... that's only in the movies ('Supernatural', with those two boys, I think) or the Catholic clergy.
a circus or a mental hospital with no funds for professional staff, especially in developing countries
With reality TV seeming to be here for good, I would take courses on communication like for being in front of a camera. The two would probably look better than a person applying for a TV ghost hunter job with no communications skills.
The food service industry is always hiring graduates with degrees in parapsychology and demonology.