Twenty some years ago when I was maybe a 5th or 6th grader, we had some family come over from out of country to visit. During a family gathering at our place one evening, we all decided to whip out the Quija board and have some fun in the back house. Being Asian and superstitious back in the day, my parents + uncles/aunts immediately knew about this board and lit some incense, saying it works best with incense and around 10-11pm.
So ok about 15 of us gathered around the table and my cousin (from out of country visiting) has her hand on the Quija board triangle thing with another male cousin. My sister sits between the two observing. They were in their teens during this. All is fun, the thing starts moving on its own and we ask a couple questions, surprised that it "answered" some things about my uncle spot on (e.g., name of his jacket, where it was made).
Anyway, my mom comes in the house, closes the door, along with this breeze, family is all giggles about this Quija board action, and after awhile we notice my cousin isn't giggling with us. We look at her and notice she's had her eyes fixated across the room, and for several minutes she never blinked at all. My sister had thought she was messing with us so she shook my cousin but that didn't snap her out.
Eventually my aunts and uncles think my cousin is possessed so they ask her some questions like who is it and if she's in my cousin. A name spells out on the Quija board (triangle thing moving with my cousin's fingers still on it) and my mom recognizes the name as the owner we bought the place from.
We ask the 'owner' to leave my cousin and it answered 'yes', but minutes later my cousin was still stiff, eyes not blinking, sorta just creeping us out. Eventually my mom whipped out some chopsticks and did some thing to my cousin's fingers which brought her out of creepy-mode. My cousin regained composure and spoke to us in Indonesian that she saw us all gathered around the table and saw her body below her just sitting there, and was wondering if she was dreaming.
My family at this point feeling creeped out decided game time was over and told the youngins (including me of course) to go to bed. My sister walks me to the front house to my bed and I go to bed with the lights on, the doors open, and the hall way lights on. I go to bed tucked in and she leaves to the back house. I remember staring at the door hoping nothing weird comes into the room and looking at the light switch thankful the room lights were on. Kept thinking about it.... but no. The lights turn off on me and I freak out, covered my head under the blankets, and kinda whimpered my way to sleep.
After that Quija board incident, weird things would happen in the back house. Occasionally during the summer and over the rest of that year, my sister and I would notice the TV turning on by itself or changing channels, rice cooker lid slamming on itself despite no breeze or wind, sudden weird chills.... that sort of stuff. I think I remember we sold the place and moved out before I started 8th grade.
Sorry wall of text, but this thread on AskReddit was super cool and fun to read.
Edit: oh yea sorry first edit. The reason why we whipped out the Quija board during family gathering was because we wanted to communicate with our recently-passed grandparents during that time. Which ... sorta went well until my mom came into the house then the creepiness began.