Carnacki, the Ghost-Finder

Detective stories in which the great Thomas Carnacki investigates the supernatural using scientific tools, such as photography, and tools that are augmented by theories of the supernatural, such as the electric pentacle, which uses vacuum tubes to repel supernatural forces.  This is  a lovely collection of chilling ghost/haunting stories, where Carnacki is an informed sceptic, willing to believe in the supernatural and protect himself from same with various rituals, yet also on the look-out for hoaxes (some of which are inspired, as you will see). The "stories after dinner" approach of each chapter works well and the haunted bits are pretty scary, much detail and not one to read too late at night!