
There's no danger, but the darkness and listening to the history of the residents there is disturbing.
Even if you have the Ghoul Mask on, which makes all the Feral Ghouls friendly to you, that place is still creepy. Too bad if you're concentrating on stalking the ghouls, you can completely miss the scares. A door suddenly flinging open right in front of you. Turning around to see that the doors behind you have shut. A lot of the Dunwich horror ( heh) is nice and subtle. By this point in the game you've already seen every kind of Ghoul in every possible situation, yet this area will creep the hell out of you. If it wasn't obvious already, you can pretty much conclude that the book you're looking for is the friggin' Necronomicon.
Once you cross the threshold of the doorway into the cave with the obelisk, you can actually hear a creepy, disembodied voice chanting "Alhazred" repeatedly.
When you find Jamie, he and a number of other mad ghouls are worshipping the obelisk in the building's basement. The final log contains mostly rambling by a fully insane, ghoulified Jaime-and repeated mentions of the name "Alhazred".
As you proceed through the building, you find numerous audio logs created by Jamie (the aforementioned "man turned mad ghoul") documenting his transformation and Sanity Slippage.
Feral ghouls, hallucinations, doors that close/open on their own, the tale of a man turning into a mad ghoul and a really creepy altar in the basement. The name alone should be a tip off that this is not a good place-it's borrowed straight out of a story by H.