Have you looked at the Forest of Spirits from the Jade Regent? As part of an Adventure Path, I imagine you'd have to rewrite chunks to make it fit, but it's a 10th level haunted forest adventure.
If you don't mind converting from 1E, pick up Dungeon Magazine #11 for "The Black Heart of Ulom." One of my favorite adventures of all time. You should just be able to plug in stats from the Bestiary and rock it.
And you CANNOT go wrong with Tales of the Old Margreve for a fantastic assortment of adventures from that dark, corrupted forest. By some of this generation's finest batch of freelancers. =-)
If you don't mind converting from 1E, pick up Dungeon Magazine #11 for "The Black Heart of Ulom." One of my favorite adventures of all time. You should just be able to plug in stats from the Bestiary and rock it.
Seconded on that recommendation. I'm actually kind of shocked that it came that early in Dungeon's run; I remember being blown away by how fresh and innovative it felt at the time. (Not to say that new ideas couldn't be found in early Dungeon issues, but whenever I've thought about that adventure I always assumed it came from year two or three, at least.)
Maybe not exactly what you are looking for but there is realm of the fellnight queen, in order to see if it's what you want you can listen to this podcast.
About one-third to one-half of Council of Thieves' Mother of Flies might also fit the bill.