All right, I'll try to answer this as systematically as I can.
The recent news of an elderly movie-goer dropping dead from an apparent heart attack while watching "Conjuring 2" brought up an old question that I'd never gotten to ask anyone
Heart-attack has many causes, it's highly improbable that the guy died from the fear of ghosts; even though there is an element of possibility.
Does the concept of "ghosts" figure in Hinduism? Do Hindus believe these "ghosts" can manifest in the physical world?
I am not sure why you are bringing up only 'Hindus'? Most of India still is rural, and in rural places the fear of the paranormal or spirituality is higher than the urban population, regardless of religion; though I have seen people with 'degrees' give way to supernatural beliefs.
As a foreign bahu who has lived in India for some time, I don't recall the subject of ghosts or spirits coming up a lot (actually, not at all).
I talk with people, i.e 'Indian people' as you put it, and I am trying hard to remember the last time I talked about ghosts. Just because one doesn't talk, doesn't mean the possibility of belief isn't there.
I'm asking because "ghost stories" seem to be few and far between in Indian cinema, and rarely do they make money. Is this because in Hinduism there are no malevolent spirits out to seek revenge on the living for a grave injustice or wrongdoing done to them while they were still living?
Bollywood is an industry led by movies that make money. First thing's first:
Bollywood can't make good horror movies,
*They fail to market them properly sometimes,
The cheap out and hire some unknown actor instead of Salman or Shahruk.
Growing up Catholic in the Philippines, we were made to believe that the spirits of our dearly departed (especially the recently departed) can make their presence felt in the physical world through subtle means, e.g. a sudden draft in a windless night, the room inexplicably smelling of jasmine for a fleeting moment, a framed photograph of the deceased falling off the shelf apparently without outside force acting on it)When my Indian mother-in-law died, no one ever shared a story of how dear MIL's spirit manifesting to them or anything. You can count on that kind of thing happening during a wake for a deceased person in my country.
Same shit; "He's in a better place." "She's in heaven." 'They'll watch over us."
People want closure that their loved ones are in a better place and happy. They seek and find solace in whatever it is they believe: jasmine, cigarette smoke, taste, whatevs.
Also, a person having a seizure (a probable epileptic fit) tends to be seen as suffering from demonic possession. I don't remember having read or heard anyone from India blaming seizures (especially mass occurrences of such, like among schoolchildren simultaneously at one place) on malevolent spirit possession.
Even back in the medieval ages, seizures were blamed on possessions; science has proven otherwise. We don't do that now because of general consciousness; that if you're child is acting weird, take him to the doc not a Baba. There are still cases of it, in some rural areas where education and rational thinking isn't the first priority.