Lockwood and Co is an excellent book where ghosts have been around forever. But 50 years ago the epidemic started where ghosts started to become more and more  frequent. If a ghost touches you die.

For the 1st 10 years no one had any idea how to beat them and to make matters worse only children could see them. Then some children discovered silver iron  running water salt and

lavender repelled them and there was one object (typically there body) that if you cover in one of the above(things that ward of ghosts) the ghost don’t appear and if you burn their earthly possession they disappear forever. Since children are the only ones who can see them people pay them to rid there homes of ghosts.

Recommended by Ben P7b