Of course I was going to love this book, and I was absolutely in no way disappointed!! It wasn’t what I was expecting (I thought it was a behind the scenes look at the series), but it was so brilliantly written and such an entertaining read and deep dive into the lives (deaths?) and histories of the ghosts! There were several where you could almost ‘hear’ them saying the things written down, and they were so true to character and so funny, you couldn’t help but laugh out loud at times. I loved the style as well - it being a collection of ‘interviews’, newspaper clippings, book snippets, paintings, etc, of the ghosts’ stories - it felt very very authentic and very real, which made it all them more enjoyable!! 
I can absolutely recommend reading it, but only if you’ve watched the series as there are a few spoilers in there!!