People who have found out that traumatic things happened where you live/lived that spirits are trapped

So first off I apologize if my title sounds botched I didn't know how to reword it. Second, my mom told me a story about when she lived with her grandmother when my older sister was in toddler years before she moved in with my dad. My sister was around 4-5 this time and she went to my mom asking "can I play with the girl in the attic?" And my mom naturally thought she was talking about an Imaginary friend. So my mom was like "Sure" and 15 mins later my sister came back and my mom was saying "I thought you were gonna play with the girl" and my sister said "her mom said she had to go". Now, obviously it could be a passing spirit but there are other stories my mom has and my mom claimed to feel bad juju when she was anywhere in that house. So now we get to my question, for anyone who has found out stories that explain why your house is haunted, what did you use? I know theres google and you can search news paper clippings and what not but I've had a hard time and it feels like sometimes AI makes it worse.