Kind of a wall of text story, but definitely worth it because even 8 years later I still get goosebumps thinking about it.
I worked in a summer camp in the US one time. It was a big thing to start off my 'round the world trip' - and being all of 19 at the time, I was super excited to see how a real life American Summer Camp lived up to my expectations from all the films I'd seen...
The camp was in the south east and really gorgeous. We were surrounded by dense woods & amazing bluffs & cliffs. The closest town was 20 miles and there was nothing but trees and canyons surrounding the camp & its lake. There were 4 sessions in the season, each going for between 2-3 weeks. We (as counselors) would get 1 night off a week, and 2 days off between sessions. On scheduled nights off we'd either chill in the staff lounge and watch movies, or hang in our designated cabin upstairs from the kids and read/listen to music - whatever. So one night, towards the end of the camp when everyone's in a groove and comfy, after everyone's turned in and sleeping soundly, I woke up at something like 1am. It was one of those times where you wake up and you instantly know something's up. My heart was immediately racing and for no apparent reason, so I lay there quietly, listening intently. That's when I heard it: a very muted cry for help, coming from outside my window towards the woods. The whole cabin was wooden, with fly screen windows, so even among the sound of crickets and other night noises, I could easily tell it was the cry of a young girl somewhere out in the woods. I got up quickly, awoke the counselor I shared quarters with and told him to listen. Once we both heard the cry again, we got outside with our flashlights and headed for the sound. It was intermittent, but you could hear her saying "help" or "I'm lost" quite regularly, and quite a way into the woods. She was clearly distressed, so the quicker we found her and got her back safely, the better for everyone. Meanwhile, we're both shitting ourselves because it's dark as hell, we have puny flashlights and she's out there somewhere with no way of seeing/navigating.
As we both cross a small playing field where the kids used to play football/baseball and stuff, we ran into a female counselor. She heard the cries while on a night walk around from her side of camp (boys & girls were at opposite areas) and was investigating too - shit just felt real. We form a line of 3 and head into the woods with our torches calling out for the girl. She was in more than we would want, but not too far that we didn't feel we'd take long to recover her. We were in about 5 mins into the woods, calling out and hearing her responses, when we heard her sniffling and crying so we knew were were close. We'd found her! She was only 20 feet away and we could hear her saying "I'm scared, where am I?" in a low voice. We kept reassuring her and just when we felt we were going to stumble upon her, she went stone silent. We called out "where are you? call out! we're here honey!" but nothing. Then, in the distance: "Help me! I'm lost! Come quick". So again, we started toward her calling out. When we felt that we were almost on top of her again, she went silent. We called. We waited. Nothing. Then, from farther away still: "Help! Can't you guys help me!?". We all chatted and agreed. 'Fuck this, we're gonna get lost in here, we have to go back to main camp and assemble everyone for a search'. We called out to her that we were going to get help and come back with everyone, and for her to sit tight cause we'll be back soon. We could still get faint whimpers and crying sounds from her, so we told her to stay where she was, we'll be back. We all sprinted back to camp, rang the big bell at the main office (reserved for emergencies only) and the whole camp was put on alert.
The camp heads put on all the flood lights and we all met in the quad for a role call/head count. All the counselors were present, all the campers and kids were present. Absolutely every single person that was meant to be at that camp, was checked off and present. With that all confirmed, we still had a question about the little girl. We had come back from the woods the same way we went in, and rang the bell & assembled everyone for inspection. In that time, we all know that no little girl without a flashlight had retraced the steps back to the camp - she was a good 15 minutes into the woods with no light, and we had a hard enough time as it was. All accounted for, everyone went back to their cabins and back to bed. The heads felt it was a false alarm and that what we'd heard were echoes of our own voices etc. We all knew that was bullshit but we couldn't rock the boat. It was creepy as hell the way the voice kept leading us into the woods further and further, and while everyone had their versions of camp ghost stories, this was by far the creepiest, real scary thing I and the other 2 had ever had happen. We chatted about it towards the end of the session, and both myself and the female counselor were confident it was something paranormal and we both couldn't explain it. The male counselor I went with refused it defiantly, and whenever we brought it up about being a ghost/creepy story he would say it was just voices echoing and that it didn't really happen... every time he defended it, I could see in his eyes that he was shit scared, and probably just wanted to convince himself it didn't happen.