There are RPGs that have horror rules in them. Such games allow the players to metagame a sense of horror for their characters. These same games suffer from far too many pauses of play while players tally up their fright levels.
The argument about whether or not certain RPG rules promote game play or game pause I will save for another time. So until then, I'd like you the reader to think about ways your group can prevent game pause from happening. I'm assuming of course that a gaming goal of your group is to role-play out scenes in real-time.
What is real-time? Think of it as movie-time. A movie with no pause button. Never do you see characters in an action film pause themselves during combat. You'll also notice that they never pause during all the other scenes either.
Now what to do with this horror mechanic getting in the way of our real-time role-play? Well, what frightens you when watching horror movies? It's not watching the characters in the film fail their fright checks because that's not done in stories.
"Stories?! I thought you were talking about movies?"
Stories are the root of all movies... as well as all role-play sessions. I won't go into it too much here. But let's just assume that a scene your group is role-play in is simply a little mini-story. And that story comes from the narrations of the GM, the NPCs, and even the PCs. This provides all the mental picturing the players need to see a capsuled action scene in their heads. Everyone sees themself as their character in a movie. Probably from a medium-shot angle even.
"So then we look up our amount of fright?"
No. The fright will come on its own time as your mental image fills in described visuals from the GM and his NPCs. Assuming, they are horrific visuals. And your role-play will determine how best your character reacts to such things. If your character reacts by jumping real quick (they're startled), roll to see if that jump is successful (use a negative modifier). Maybe you jumped clear. Maybe you tripped up. Either way, anything else you try to do at that moment will have a negative modifier because you are busy getting out of the way.
The GM quickly describes what happens next, with another horrific visual added. And so on. Within moments, you'll realize that a horror mechanic is not needed at all.