I keep having these really vivid hallucinations/night terrors of a spider hanging above my head while I'm lying in bed.  It happened once about a month ago in DC, and it has happened the past two nights.  They look so real, spinning webs right above my head.  I've woken up practically screaming both times, jumped out of bed, and by the time I've fetched something to knock the spider down with, it has magically disappeared.  It took me about ten minutes to realize the first night that it was just some sort of vivid image.  Like my brain is still in dream-state.
The second night, I woke up, and watched the big, brown spider crawl across a strand of silk towards my lamp.  As it got brighter and brighter (I left my lamp on out of laziness, and it isn't very bright) it gradually dissipated into nothingness.  It was extraordinarily surreal and creepy.  I was wide awake and seeing it disappear before my eyes.  Just like a ghost in a movie.  I have no clue why this is happening to me, but I hope it stops, because I'm truly terrified of spiders and I can never tell if these images are real or not.  Even after I watched it disappear last night, I still kept a ruler next to me in bed in case I had to swat it away.  Don't ask me why I grabbed the ruler.. I just wanted something long so I wouldn't have to let my hand close to it.