When I was in military camp a few years ago, there were a few cases of possession and eye witness accounts of spirits, and it was pretty terrifying to me when it all happened right near my dorm.
There were a few friends of mine who detailed seeing ghosts during the night, especially at the toilet areas (which is next to every dorm) and such.
Things got worse when a girl got possessed right near the neighbouring dorm and started shouting. I wasn't there but I did saw a crowd gathering at the site and witnesses saying they heard her voice went from high pitched screaming to a deep, low toned voice (in her words, "like a middle aged man"). That kept me up at night for a few days.
After a few days from the event, I heard of the news of another girl getting possessed and reacting much violently in the camp's mosque and a friend of mine (who was there) detailing that she saw a very dark shadow figure standing above the possessed girl before she(the friend) fainted. After a while, when we were all gathered at the mess hall, I could see a few staff members gathering in a circle at a certain spot (which is near the girls' dorm entrance, to which where my dorm is located at). While it was very far, I could see them praying at that spot (include other religions, not just muslim, so it must be pretty serious). The friends with third eyes (that's what they called for eyes that could see what others can't normally see) said they could see a dark shadow reacting violently in the middle of that circle. I grew even more agitated cause I knew it's getting very unsafe for us (spiritually).
What made me break down in lights of the supernatural events was when I got back my religious necklace from a friend (I lent it to her for a few nights) and it broke right in front of me (she barely tug on it). This made me thought the negative energy was getting very strong and dangerous that it could break a protective accessory. It made me really scared and very desperate to cut short my time in military camp and go home. I can't see nor feel their presence (according to an instructor, I have a strong spirit that prevents such despite being a huge wuss and only being partially religious), but it does not mean I shouldn't be afraid of the things they can do that a normal human can't.
I calmed down after a long while and completed my military training thankfully. But it made me very wary of any attempts to mess (whether for interested communications for jokes) with spirits, that I'd either cut in and try to stop their attempts or avoid them all together.