This is way out there...
but a few years ago i used to listen to the art bell show (radio show about paranormal/aliens/conspiracies/etc)...
And a few times there was the topic of shadow people -- shaped like humans but invisible (except in rare occasions where you might see one)...
One guy once called in saying he was able to see them. And once when he was staring at one it realized he could see it and it was startled.
I dunno what to believe of the shadow ppl thing but maybe your seein em.
