I have 2:
I was laying in bed with both kids (baby and preschooler, they're not 16 year olds lol) and my husband.
It seemed like I was in a half-awake kind of state. I was cuddled with the baby. The bedroom door was wide open, with the bathroom light on for child-comfort.
All of a sudden, I see a very tall figure, taller than the door frame, reaches it's long arm in under the door and wraps around the inside wall. It was wearing red. I couldn't see it's face, just the right side of it's body, as it's head would be higher than the frame on the other side.
As he slowly crept in the room, I couldn't move. I felt my heart race faster and faster. I'm trying so very hard to scream, to wake my husband. He was laying behind me.
All I could do was try to scream, watching this figure come into my room, in the middle of the night. I couldn't hide my baby from it. I was losing my mind. I started to shake, trying to yell.
Eventually, I "woke up", screaming my husbands name and shaking around.
He shot up, thinking the world must be coming to an end or something (I felt so bad for scaring the shit out of him).
Eventually, after staring out of the room for a solid 20 minutes, I fell back asleep, exhausted.
TL;DR: I've only experienced sleep paralysis once in my life, just a couple weeks back. I've never felt such fear ever before in my life.
About 3 years ago, my husband worked 3rd shift (gone at night). We just had our son a few months ago, so it was just me and the baby at night. This was fine, until one night.
It was 2:20 AM on a hot summer night (alright, technically morning). I had the bedroom window open, I had the fan on and the T.V. as well- to fall asleep to.
All of a sudden, the bedroom door is busted open.
For a split second, I thought "he's home early?" until I heard- in an unfamiliar voice- "ARE YOU IN HERE?!"
I froze. With my back to the door, I could see the silhouette reflection of this man in the glass of the window (which I was facing). This wasn't my husband.
I didn't say anything, too afraid. I just lay frozen, eyes wide, panicking.
Then he shouted "FINE. WHATEVER!" and slammed my door shut.
I quickly, but gently- not to wake the baby- covered my son up with the blanket. Instantly thinking I was about to be murdered, I didn't want him to get the baby.
I frantically tried to think of where to hide my son, but I couldn't leave the bed because the floor creaked, he'd be able to hear me. I thought about the dresser drawer, or the closet- but he'd hear me moving, so I just covered him.
I conveniently slept with my cellphone, to occasionally text my husband at night.
The first person I called was my own mother. Why? I guess you instinctually go to whoever has provided you the most comfort over the years.
She didn't answer.
So I called my mother in law. She did happen to answer, I -in a terrified voice- told her what was happening. She yells at me to call the police, to which I do.
I get the dispatcher. She asks the usual, with me crying "Someone's in my house! Why are they in my house?!". The police are on the way, and get there fairly soon.
I hear them come in downstairs, and up to my room. Nobody was in the house anymore.
They asked me a few questions, I answered. Until they asked the one question that scared the ever loving piss out of me...
"Who's been living in your basement?"
"There's some stuff under your basement stairs. Anybody else live here besides you three?"
No. At least...not that I ever knew about...
TL;DR: An unexpected room-mate.