I like the facility idea, like in Shutdown, I still get chills from that and bug spirits still get me too. I was GMing recently and got lazy and stole the shedim filled hospital from Romero and Juliet but in a much larger facility and during it I slammed my hand down on the table and everyone jumped. It was funny and great until I got hit with a Mountain Dew bottle.
I recently ran the Ghost Ship framework from Ghost Cartels' Hong Kong section and was playing up the creep/horror factor of the abandoned vessel on the ocean. When one of my players stepped over the body of one of the 'dead' sailors, I grabbed his arm as the sailor grabbed his leg and had to kick in my reaction enhancers to duck the reflex flailing.
Horror does work better in small doses, but establishing a horror vibe through storytelling technique (no distractions/background tv, speak slightly lower so the players need to devote a touch more focus to listening, buildup of tension through lift and release, etc) is far more important than enforcing a 'you're screwed' rule set. It'd been 12-13 years since I ran my long-term Ravenloft campaign, but as soon as they boarded that ghost ship, I could see the past years of psychological trauma begin to bubble to the surface. Gamer PTSD, make it work for you.
- Wailer
* - Also, use what you know about your players to your advantage. If something freaks them out irl, it's usually an easy scene setter. Less is often more, though. If a player is afraid of spiders, fighting a giant spider might gross them out - but descriptions of packets of scuttling spiders slipping through cracks in the walls will give them background jeebies that can work you you - and if a spider just happens to land on the arm of that player as he takes a simple action to steady his aim in the next combat, be prepared to /popcorn.
- Wailer