I fell in love with the TV adaptation of this story decades ago, but only recently went searching of the original story.
Well, of course, the two are very different. Oscar Wilde's book is much more about the ghost's comeuppance, with a firm jab at American consumerism and involves a lot more children in the household. Those kids pranked Sir Simon so ruthlessly I felt sorry for him as I was giggling.
Virginia's efforts to help the ghost move on hardly take up a chapter and there's nothing at all about what happens to her after she passes through that wall with Sir Simon.
Of course I like the book better; but the TV adaptations have their charm too; they are almost equivalent to fan fiction, as they take the story between Virginia and Sir Simon further than Wilde did. I think this might be a fun one to read to my nieces next Halloween.