How to activate and deactivate an actor in a map using a trigger box?

Sorry for my bad english.
Is it possible to deactive an actor in map and activate it again when player trigger a box? for example i have a room with a door. i want to put deactive enemy characters in map and active them when player come in to room and trigger the door.

You want to deactivate just the actors or can you deactivate the entire room behind the door?

If you can do the entire room I suggest you look into level streaming as this does exactly that. Also, you use a trigger box to load the level which also does what you need it to do.

Actually, you can make a streaming level in the room and add only the actors you want streamed, if for whatever reason you need the room to exist at all times.

Thank you, can you give me a tutorial link about level streaming please?

Also I was working on streaming a bit the other day: