My cousin owns a 170 year old plantation house, reputed to be haunted. She’s seen and heard some things. OTOH I’ve stayed there a few times, including once all by myself. Nothing ever happened out of the ordinary while I was there.
Another friend and her husband renovated an old tavern in MA, where they lived for a number of years, and she saw things, including a feather that appeared out of thin air and floated to the floor. She’d smell flowers, when there were none in the house, and one day when they came home...having left their twelve year-old son home alone...he met them at the door and wanted to know who the old man in the nightshirt was. Evidently he’d been on the front stairs when the old man passed him, climbing upward, carrying a candle.
Only later on did the owner of the house admit to his wife that the first night they’d slept there, he’d waked up to see an old man flanked by two women in old fashioned clothes standing at the foot of their bed, staring at them. After a moment, they faded away...having checked out the new owners!
Here’s another MA story. A friend who owns an antique shop had moved into an old house on the town green. Not long afterward, she got shoved in the back and almost fell down the stairs in her house. (She was alone in the house at the time.) She caught her breath...at the foot of the stairs, and had a talk with whoever had pushed her. Assuming it had been a former owner, long dead, she said, “Look, we’re living here now and I promise we won’t do anything to the house that you don’t like. But please let us live in peace.” Evidently it worked, because since then she hasn’t been shoved in the back on the stairs. But she certainly believes in ghosts.
The brain is pretty amazing. If you stick an idea in your head (you look around and see some cues that make you feel creeped out— even something simple like darkness), it can fully develop it in real-to-you ways.