need help with horror game environment

hi everyone
i was wondering about what i should to make the environment of my game look scary
the settings are in an old castle
i need to know about the the light and props that i should place
p.s: i finished making the story

No light or only a bit.
A chair ,a desk, one dish, two spoons, one broken window, no doors(because i hate them, when they locked).

Lots of blood all over the place, lots of torn flesh, dead animals, bloody knives, maggots, flies, rotten fruits lol

Sound is integral for a good horror. Consider ambient sounds or the lack thereof.