There are evil things. A guildmate of mine has a fixture on his ceiling that rains blood, spooky hanging lanterns, and this pile of glowing flaming skulls that doubles as a light fixture. Not to mention his giant statue of Molag Bol.

There are also craftable cages and things. I am pretty sure there are skeletons and such you can buy as well. Or the craftable target dummies could work. The Dark Brotherhood also has things from the daily vendor/hireling type guy you can get with RNG - hearts and blood vials and such. And I am pretty sure I ran across a mound of flesh atronach parts for sale somewhere... And I can personally craft meat hooks with meat chunks on them.

I also have a bit of a creepy thing going on with my main house (nicknamed the "Creepy Murder Hut") with cheap materials. You can tell a heck of a story with the undaunted busts, some crafted candles, and a small assortment of crafted white items like crates and knives and hatchets. Mine was just to play with some of the cheap items available to get a feel for positioning things with the housing system, but it took on a life of its own. My guildmates were amused because it seemed so out of character for me... But that's the fun, isn't it?

Be creative! You will think of something.