Fortean Times has an article on haunted lighthouses. Apparently many of them, especially deserted ones, are claimed to be haunted.
It seems odd, since there have been very few recorded deaths in lighthouses. The sceptical part of me notes the unusual acoustics of a tall, circular building combined with the noise of the sea and the human imagination after dark. Even so, there have been too many reports to dismiss in this way.
Some involve sightings (from outside) of a figure at the top of a locked and abandoned lighthouse. These are not easy places to break into. Many reports of sightings and voices took place in daytime.
A lighthouse keeper is a solitary individual by nature. It's not a job for the socialite, it's for those who prefer to keep away from people. Those who might, in other times, have become hermits. It is therefore likely that, after death, the spirits of these people would seek sanctuary in the place they felt most comfortable. It's also not surprising that most reports involve antagonistic spirits who want to be left alone. That's all they ever wanted when they were alive. They don't want to cross into whatever spirit realm there might be. They want solitude.
Access to lighthouses is difficult. Working lighthouses naturally don't want anyone getting in the way because if an investigator blew a fuse and put out the light, it would put shipping in danger. It's not a responsibility any investigator should take lightly since there could be some serious legal repercussions. I have 'professional indemnity insurance' in case I damage someone, or someone's property, during the course of my work. It won't cover the sinking of a trawler!
Abandoned lighthouses are likely to be extremely dangerous structures and are often inaccessible. Getting permission to spend the night in one will be difficult and if something happened (something physical, like falling down the stairs) it would take a long time to get help. If a storm blew up you might be stuck there.
I have never investigated--or even set foot in--a lighthouse but I'm certainly going to see if it's possible. It might not be but it's worth a try. Most of my investigations take place in lonely places, away from the hubbub of the town and the constant interference of wildly fluctuating electric fields. I find the real silence and the real darkness away from the town and the streetlights relaxing, and much easier to work with. Fewer interfering variables and almost no interfering living people makes an investigation so much more likely to succeed.
I hereby add lighthouses to my list of potential places. One day, I might get that chance.