I have been staying at my cousin's house for a couple of weeks now and up until now everything has been normal.
The room I am sleeping in is diagonally across from a staircase leading downstairs. I am a very light sleeper and often get up to get a glass of water. I was going downstairs to get a drink and I thought I saw a dark figure next to the banister. I ignored it, went down stairs. As I got back to my room I turned to shut the door and saw the shadowy figure again. It stood around 5'-7"/5'-8" a bit taller than me. I thought it might be a family member so I walked closer but it just vanished back into the shadows. I couldn't find anything that would be making that kind of shadow and I'm pretty sure it wasn't a trick of light.
I stayed up the next night to try and see it again but it wasn't there. Two days later I saw it again. It was just standing leaning against the staircase. I got scared so I shut my bedroom door and went to bed. It doesn't seem to appear at a certain time as each time I get up, it's always a different time yet it's still there.
I asked everyone else if they had seen anything but they hadn't. It didn't seem to bee threatening but it still really spooked me.
I have not experienced this before and would just like to understand what this figure is and if it is possibly harmful. I also would like help understanding why only I can see it. My sister and cousins occasionally get up during the night (all bedrooms are on the top floor) and they have never seen it.
Any insight would be very useful and appreciated.