I'd like to share an experience that happened to me when I was 15 (I'm 17 now). I used to stay at Jorhat on a rented house with my parents. Although I'd never experienced anything like this in the house before and I'm not sure if it was just a hallucination or something else, but this experience scared the crap out of me.
Couple of days ago before this experience, my grandparents came in to stay at our house since we hadn't seen each other in months. You could say it had almost been a year. After one or two days, my grandpa decided to leave my grandma at our house for a week or two then come back and pick her up and leave for their village. Everything was normal. I've mentioned before nothing was wrong or even felt wrong at that time.
My grandma was a little bit sick. Me and my sister have been sharing one bed with each other since childhood. We don't mind sharing the bed with our close female relatives and grandma wasn't an exception. We already have had been sharing the bed with one of our female cousin who came in to stay with us couple of months ago. The bed is huge enough to fit four people and it was one of those chilly weather so we decided to sleep altogether: me, sister, cousin and grandma. Personally, I don't like sleeping towards the open ends. I always need to sleep on that side of bed which keeps me facing towards/near the wall.
We all had a sound sleep except in the early morning when my sleep was suddenly broken. When I opened my eyes, I was facing away from the wall. There's a huge window on the wall through which every morning the light of dawn breaks into our bedroom. I turned around and had the greatest shock of my life. I saw a lady with her back facing towards me. She had a really long, black hair. I couldn't make out much of her other features as I let out a scream and immediately tucked my head inside the blanket. I was so damn scared. For a second, I thought it was grandma but how could've she got up so fast from bed and reach there at a lightning speed. Note that there was a little space between the bed and the window/wall. And whatever I saw, it was almost the same size of my grandma. She wasn't moving, she was just there, standing, facing the window. My scream woke up my cousin and she asked me why on earth I screamed like that in the early morning. I told her what I saw. She dismissed it as a bad dream.
Later, when I told my mom about this she said nothing but stared at me like I was a lunatic. Well, even though I'm not much of a skeptic, I'd still like to think it was just a bad dream or hallucination rather than an apparition. She didn't see what I see. It just disappeared after I tucked my head inside the blanket.