I have a handful of things though I don't believe in the supernatural:
1. When I was around 8 or 9 I was afraid of my sliding door closet being open at night so I always made sure it was entirely closed before going to bed. One night I woke up around 5 AM to see the closet was wide open and something large on the top shelf was glowing green, it looked like a blob. I freaked out a bit and hid under the covers, when I looked out from under them what ever it was was on the floor moving towards me but stopped suddenly like it was startled. I stayed up staring at it until my father woke up for work shortly after. I called him and once he opened the door it disappeared with the light.
2. There was a long abandoned farm house behind my house that we would frequently explore. The creepy part was that the basement was always covered in about an inch or two of ice regardless of the season or temperature. Beneath the ice were tons of posters from kids shows like Ducktales and Darkwing Duck. The house was still fairly furnished including photos of the family that lived there previously, it looked like they left their life there. One small room was almost knee deep full of action figures. The shed in the back was overflowing with computers and monitors. I'd say there was probably 40 of them. It also had a regular looking door in a hall on the 3rd floor that looked like it would lead to a room but it lead out to nothing but the side of the building, no stairs or ladder or anything but a 3ish storey drop.
3. I was about 13 sleeping over at a friends house playing Sega Genesis. We were in the basement and it was getting late so we were about to get ready for bed. He stood up to grab some blankets and it startled his dog and it ran up the stairs. Suddenly we heard the sound of rushing water coming from the back room. There was a bathroom back there but no one but us had access to it. We went into the bathroom and sure enough the tap was running full blast with his dog sitting in front of the sink trying to jump up. We have no idea how his dog got into the bathroom as it would have had to come down the stairs and cross our path to get in there. We didn't sleep that night.
4. I was walking home from my girlfriends house at about 3AM and walked by a house which has a large backyard that is fenced off with about 12ft hedges. As I began to pass I heard something that sounded like 2 people loudly arguing in what sounded like Russian as well as light passing through the hedge. I assumed someone was having an argument and holding a flash light. It was startling so I just stood and listened, as I listened I realized it wasn't Russian but still sounded like people arguing. It sounded very bizarre and other-worldy (sort of like when E.T. screams) and began to sound sort of static-y. It was very loud. The bushes started rustling and the light started flashing more. So I ran past the bushes worried something was going to come through the bushes and it started to calm down. I got to where the opening into their backyard was, but nothing was there. I assume it was probably racoons fighting but I don't know what would explain the lights I saw.
5. Driving in the middle of no where. Farmland and forests everywhere. We were searching for a fabled "Ghost Road" in south Ontario where you can see a "Ghost light" which was supposed to be a headlight that follows you of a biker who died in an accident after crashing into a rock, but we couldn't find it. As the road we were on began to turn to dirt and it seemed we were driving into a forest we decided we should check our phones to see if we past it. We got out of the car for some fresh air and a friend was exploring around. The only light you could see was from the moon. My friend called us over to look at something and brought us to a huge open empty muddy field, probably a couple of acres across. In the centre of the field were 2 Chevrolet Bel-Airs that were in really good condition, sparkling clean facing opposite directions, looked like show cars. Classic Ontario license plates as well. Wasn't a house or anything in sight for a good while so we had no idea why they were there.
6. Came into my room one day to the sound of someone groaning loudly like the popping, crackly "uhhh" sound you make from your lower throat. Searched the room while creeped out for awhile and found a furby buried under a bunch of blankets in the closet. It's eyes were rolled back and half closed with its mouth open and making this un-ending "uhhhh" sound and the occasional slowed down "Waylo-koko! Huhhuh!" and start dancing then back to "uhhh". I couldn't find a screw driver to take out the batteries so I threw it in the back room in the basement. It lasted for a couple weeks.
7. My elementary school had a large pit area near the playground. I think it was made to collect rain water and had 2
large storm drain tunnels. They were completely blocked off by bars and even as a young kid they were difficult to climb through. One day during recess we dared each other that we wouldn't climb through the bars and eventually we all climbed through. We then began to dare each other that we wouldn't walk deeper into the tunnel where it was almost pitch dark. Me and a friend began to walk deeper when we heard a scream from within and saw what looked like a kid dressed in all white run across where the tunnels crossed deep inside. We ran out pretty quickly.
8. Not remotely supernatural but very creepy. I was in LA for E3 last year and my girlfriend and I stupidly stayed at a hotel near MacArthur Park. Got off the subway to see a man in his 30s with his pants down holding his dick, waving a pistol in the air and yelling at 3 14-15 year old girls that he was going to shoot them if they didn't have sex with him right there. He kept yelling "Do you know who I fucking AM!?!?!"
9. For a couple months a few years ago we would receive multiple phone calls a day which would only be the sound of what sounded like a cassette tape running and occasionally someone breathing with no response but occasional laughing in the background. We'd receive this at any time even during the night or in succession up to 3 times. We eventually called the police and they said it was from those Window's virus call scam centres, they have an automatic call system and if everyone was busy with someone it would just go to an empty machine or something. Still scary even after knowing that though.