Don't go there. Your first, preparatory visit to the site should be during daylight hours. In the daylight, check for anything odd. Listen for local traffic, factory noises, trees that creak, and so on. Plan your next visit for an actual, ghostly encounter.
Most ghosts appear at dusk, or after dark.
The hour immediately before and after dusk and dawn can be the best times to visit. Some ghost hunters insist that better hours are 9 p.m. to 3 a.m. However, some ghosts manifest happily during daytime hours. It will depend upon your schedule, and when people have seen the ghost in the past. Personally, I've encounter ghosts at 11 a.m. and any time after that.