I have some good ones for this topic. The first two are just coincidence that's entertaining but the third is coincidence that made me think.
1. My wife and daughter were out of town and I had the house to myself. I am pretty hardcore skeptical but I like to watch scary movies to TRY to give myself the creeps for fun. I had all the lights off in the middle of the night and watched Paranormal Activity. I was perhaps 2 on a 10 scale creeped out when the movie ended. Of note if you haven't seen the film, there is a demon that kind of lives in the basement of the house.
I get up to walk to my kitchen and out away the snacks and as I pass by my basement door I heard
this coming from down the stairs. My daughter had that toy, but hadn't played with it for several years. It had never before or since spontaneously activated.
2. This is a gaming story to fit the theme of the boards. In the early 90s we were playing a session of the RPG Chill. The GM was doing their best at making the session a spooky one, so the lights were dimmed and people were trying to get into the spirit of it all. At some point in his narrating that evening the GM said the words "And then suddenly the phone rang...." which was a jump scare moment in the narrative, but at the exact same time he said that the actual phone in the room with us rang making us jump out of our seats.
We all congratulated the GM in the excellent prank to go with the session but in actuality it was pure coincidence, the phone call was someone for his younger brother. Amazing timing.
The next one is long.
3. This is a story that means a lot to me and it has done a lot to move me from Mr. Cynical Science to Mr. Who Really Knows. Its too coincidental to be just coincidence.
My best friend growing up was Ernie. I met him in 3rd grade when he moved next door. This would have been 1981 or so. He was my first D&D buddy, although we really didn't know how to play well and eventually his mom made him get rid of his books during the Satanic Panic (he just gave them to me!).
As a young adult I had moved around a lot, but no matter how far from the town we met I went, I would always visit with Ernie when I was back in the area or he would travel to visit me.
Eventually in the summer of 1995 I moved back to the area we lived as kids and I could hang out with Ernie again on a regular basis. Late that fall he was in a fatal car accident and my best friend was gone.
Neither one of us were religious and both of us were pretty skeptical about all things supernatural. We did have an agreement with each other that if there was a way to come back in an afterlife we would swear to do it for the other. The previously mentioned Netflix show Midnight Club had kids making the same promise.
After Ernie passed I had always hoped to hear from him somehow, but nothing really ever happened beyond an occasional dream, but that's to be expected, not even remotely a sign. I dream about people I care about constantly.
Fast-forward to around 2015 or so. In that time ive met my wife, gotten married, adopted a daughter, and got on with life. My wife is actually somewhat religious and would regularly attend the Greek Orthodox Church. When she moved to my town she never found a church she felt a big connection to, so she would occasionally bounce around and try different ones. I would never go to church with her (I'm an agnostic) but would accompany her on Christmas Eve because she would be out very late by herself.
That year my wife chose to go to a church Inhad been to before. It was the church that Ernie's funeral service was held at the day he was buried. This was the first time I had been there since 1995 but since it was his families church I figured I might be able to see them after the service and say hello.
The church does the normal Christmas Eve service and as it is winding up they say they have something special to do that evening. They call up an adult woman with a baby to the front. I recognize the woman's name as being Ernie's sister. When she gets to the front they announce the special thing they have for the evening.
The priest/minister/father (sorry I forget the title at that church) tells the congregation that the woman had a brother who used to go to that church in the past, but that he had passed away young when the woman was still a girl. Because she loved her brother so much she wanted to honor him that night by baptizing the baby and giving it the middle name "Ernest"
This night had really made me wonder about how bright a sign had to be before you call it a sign and not just coincidence. It has made me soften my stance on thinking I have everything figured out.
Note: I'm not 100% certain on the terms like baptizing and such. I'm not super familiar with that church and its customs, but the gist is "some church thing that's important to babies and I'm doing this one to honor my brother".