Pubs - Don't forget ghosts are usually good for business and they are often found in hotels too. So invention or elaboration is perhaps more likely in the case of pub ghosts than in other areas
I suspect it's a chicken and egg situation. After all, why do the majority of people go to a pub .... to have good time, or in the hope of seeing a reported ghost? I feel the answer would be the former.
Also, in reports I've read, it's rarely general patrons who witness pub-ghosts. Usually, reported sightings are made by pub owners and staff, after-hours.
Those who report ghost-sightings are very often subjected to cynicism, scepticism, accusation, derision and ridicule. Pub owners have more than enough work, worry and problems on their plate, without inviting snide comment about their mental stability and/or fitness to run their establishment.
Ghosts are witnessed in factories, private homes, pubs, stables, roadways, etc. Pubs of course tend to be more well-known than many of these. Even if someone has only passed by the pub in question, or stopped there briefly for a drink twenty years ago, or lived in the locality for a period, they tend to remember it and/or identify with it, because a pub has a name (The Black Dog, for example) and because pubs are a landmark often throughout several generations. So a pub-ghost story may well be repeated more often than a ghost-story involving an ordinary woman in an ordinary row-house in an ordinary street. Familiarity breeds contempt and things lose their sense of urgency and freshness the more they're repeated -- particularly if the tale's accompanied by jocular comment about the pub-owner's imbibing after hours etc. As consequence, pub-ghost stories tend not to be taken as seriously and they may not be regarded as particularly 'scary' because the public regards a pub as a hive of activity, filled with people and noise and usually near a busy road or intersection. The public isn't familiar with the pub itself, or its atmosphere, when it's closed. The public isn't familiar with the basements and upper rooms and attics and quirky little cupboards and boarded up sections. The public has no idea what the place is like in the dark, or what it's like to be there alone at four in the morning.
Pub-owners, particularly those in tough neighbourhoods, would generally be loathe to tell patrons that they've seen a ghost, because it would lessen their aura of no-nonsense capability & strength of mind and purpose. The tendency to see ghosts is associated in the minds of many with a delicacy (weakness) of mind. Those who claim to have seen ghosts are often regarded as less than reliable or trustworthy. A pub-owner in a tough section of town has to be able to quell disputes and problems by his manner, first and foremost -- otherwise he'd be embroiled in physical brawls any time he refused to give further credit or drinks after closing. A pub owner has to command respect or he'll have more problems than the job is worth on hourly basis. Fine for a barmaid to tell people she's seen a ghost, but a pub-owner is likely to deny any ghost he may have seen until after he's departed that pub.
After a series of pub-owners and staff have revealed (reluctantly or otherwise) that a pub is haunted,
then the sightseers and ghost-hunter crowds arrive. The odds of seeing a ghost whilst sipping a pint are fairly rare though I'd imagine, and people aren't so silly that they're not aware of that.
Obviously, it doesn't hurt profits if it's claimed in travel brochures that a pub has a resident ghost that periodically appears in the upstairs bedrooms (which just happen to be available for X dollars per night per person). But pubs in tough areas of Manchester thirty years ago didn't as a rule attempt cater to sensation-hungry tourists or ghost-hunting groups. As well, most patrons in that and earlier eras would have had their share of personal paranormal experiences and would have heard more from family, friends, neighbours and workmates, just as we do today.
So while its a fact that some pub-owners use genuine or exaggerated resident-ghosts to attract custom, this doesn't mean that ghosts have not been witnessed by pub-owners who made no attempt at the time to publicise or profit from their experience.
As to why so many pubs are reputed to be haunted, we need simply examine the reason many people go to pubs in the first place. A pub's primary trade is in alcohol and alcohol is often used as anaesthetic; as a means of escaping for a while the pains and realities of life. So a lot of emotional pain and suffering is present in a pub at any given time. It's to be suspected that persistent ghosts/spirits may also be trapped within a mass of pain and/or unresolved emotional suffering -- otherwise why would they continue to hang around this plane? They say that misery loves company and it may be that earthbound spirits identify with many who rely on alcohol. It's even been suggested that alcoholic ghosts attempt to satisfy their thirst through live-alcoholics and even take full or partial possession of them. So perhaps pubs are a natural magnet for certain types of earthbound spirits.
As well, pubs provide lodgings for members of the public and it's probably true that many people in deep emotional turmoil have occupied rooms in a pub. These days, motels are often chosen by those intent on committing suicide. In times past, they would have taken a room in a pub. If they died in deep emotional distress, this may have caused them to remain in the place where they were last alive. Or perhaps for many ghosts, their happiest hours were spent in a pub while they were alive and so they stay? And of course, most older pubs have seen more than their share of physical violence, etc. They share this in common with certain bridges, railway stations, underpasses, highways, fields and houses, etc., which have reportedly witnessed ghost sightings too.
Perhaps the reason pubs gain publicity re; ghost sightings (apart from profit for their owners) is the contrast in people's minds between making merry and echoes from beyond the grave? Perhaps it's because a ghost in a lively pub seems so incongrous as to be novel, entertaining, less threatening or more interesting than the standard ghosts-in-the-graveyard?
Whatever the case, I doubt the OP's big, capable pub-owing father would have undertaken to arrange an exorcism until the point he was convinced it was a necessity. The pub was his livlihood. And people, especially practical working-men used to dealing with their problems on their own, do not take matters such as exorcism lightly. Nor do the clergy.
As to the failed exorcism; these are said to be highly dangerous for all concerned. It's generally believed it's best not to conduct exorcism at all, in preference to having it fail.
I was persuaded to assist in an exorcism. I did so reluctantly, in the belief the standard latin ritual would be followed to the letter. This was not the case. Later that night, I was visited by an immensely powerful entity who appeared behind me in my living room some 90 kilometres from where the exorcism had been held. The entity issued the following threat: ' You've got rid of the rest of them. Now you have me to deal with'. So exorcism doesn't always work as intended and it can be very frightening for those involved, as the OPs father learned when he was pushed by unseen hands into the pumps. Still, we have people enchanted with the dark side and who feel all they need is the latest book of spells and some black lipstick, a camera and a few friends beside them before they launch themselves into god knows where. Telling them to err on the side of caution is a waste of time. Some people like to learn from their own mistakes. Their choice, of course.
