What is a ghost or spiritual experience (good or bad) that has happened to you, that made you believe theres 'another side'?

When I was about 17 years old my grandma moved into my parents house with us as she was showing signs of dementia. I was home alone one morning when my parents went to work and I woke up and got something to drink and went back in my bed. My grandmas door was closed so i assumed she was still sleeping. As soon as I got back into my bed and pulled the covers up my whole bed started to shake for about 15 seconds. I sat up and looked around and thought wow was that an earthquake? Which was very weird because I live in the Midwest and we do NOT get those. For some reason, I just got a strange feeling that I should check on my Grandma. I opened her door and called out her name. When I looked at her, she was laying in her bed with her eyes open not moving. I immediately ran over to her, she was still breathing and I called 911. Right after I called 911, I called my sister who lived RIGHT down the street from us and she came rushing over. We found out she was in a diabetic coma. While the ambulance is taking my Grandma out, i said to my sister "thank god for that earthquake otherwise I would have just fell back asleep. She looked at me very confused and said "What earthquake?".