a ghost story

literally everything is the same except ghosts exist

ghost formation: classic ghost thing of "ghosts are souls who aren't 'ready' to leave yet" except this means that in leave the light on, ghosts most commonly form from people who suffered particularly tragic or brutal deaths--ghosts from natural deaths (as well as older people in general) are extremely uncommon.
those who become ghosts commonly do not realize it at first as they usually have no recollection of their death, nor the moments leading up to it (although there are some exceptions, usually those who are particularly vengeful).

ghost visibility: although ghosts are usually only visible to each other, they can develop the ability to take on a corporeal form that is visible to those who are alive. this requires practice and expends energy, and even then, ghosts may find it difficult to show themselves to those who are hardcore skeptics or otherwise "closed off" to the spiritual world. while invisible, ghosts can still physically interact with material objects if they wish to, but not people (even if some "spiritually inclined" can occasionally sense their presence).

pictures: while invisible, ghosts may still appear on photos from film cameras; appearing on a photo from a digital camera is near impossible. in photos taken while visible, ghosts often appear semi-transparent or otherwise distorted.

still have to decide more things but

my weird romanticization of dreary coastal towns and lighthouses, my morbid obsession with ghosts, and my wholehearted desire to form a band with my best friends