Greenwood Ghost tours?

Green-Wood's historian Jeff Richman gives tours every year. They are VERY well attended.

October 25, 2008, Saturday
1:00 PM - HALLOWEEN AT GREEN-WOOD, PART 1 - A WALK. Celebrate the holiday with fascinating tales of murder, mayhem, and Spiritualism. A visit to the Wizard of Oz and the Catacombs is included. This is a very, very popular tour, so arrive early. This special tour is $20; $10 for Historic Fund members. No reservations necessary.

October 26, 2008, Sunday
1:00 PM - HALLOWEEN AT GREEN-WOOD, PART 2 - A WALK. Celebrate the holiday with fascinating tales of murder, mayhem, and Spiritualism. This is a very, very popular tour, so arrive early. This special tour is $20; $10 for Historic Fund members. No reservations necessary.

There's also their night time flash-light tour:

October 11, 2008, Saturday
6:15 PM - SATURDAY NIGHT BY MOONLIGHT, FLASHLIGHT, AND FOOTLIGHTS - A WALK. Bring a flashlight, sign a waiver of liability, and you're all set. This special walk features live accordion music, a visit to the Catacombs, and the light (weather permitting) of a full moon. No reservation necessary. Admission is $20 for the public; $10 for Historic Fund members.

Check with Big Apple Tours, they might be running something...though not at night.