Personally I believe in opening doors/inviting bad things but that sounds more like sleep paralysis/night terror. Then again maybe that's a bit of a gray area.
I do remember hearing that people tend to have dreams based on the last three hours they're awake, so maybe try watching lighter/not murder-y shows before going to bed.
I do remember hearing that people tend to have dreams based on the last three hours they're awake, so maybe try watching lighter/not murder-y shows before going to bed.