I don't know if I believe in ghosts, but I do believe in spirits. Most of my stories have to do with deceased family members.
One night me and my Mom were home alone and my Mom was in the kitchen and I was in my bedroom. She came in and asked me if I had just been in the kitchen, which I hadn't. She swears to this day that somebody threw a spoon at her. Later that night, we were in the living room watching TV and a lamp kept flickering on and off. Thinking that maybe the plug wasn't pushed in the outlet all the way I looked at the outlet, and the lamp wasn't even plugged in!! What is really weird is that without even thinking about it, I calmly said to my Mom, "Oh, it's just Grandma." Later that night my Mom realized that it was a year to the day my Grandma died. There's a little back story to the spoon too. Apparently, shortly after my parents married they went to visit my paternal grandparents. My Grandma was a bit of a curmudgeon. I guess she counted her spoons and one was missing. . .and she accused my Mom of stealing it. My Mom said why in the world would she want to steal one of her spoons? And everybody, knowing how my Grandma was, just blew it off. It probably just went missing, but I think my Grandma always thought my Mom had stolen it.
Another time, about a year after my Dad died, my Mom told me, "I saw your Dad last night." I asked her what she meant and she said he came to her in a dream. . .and I guess they had quite the conversation. Doesn't seem too odd. . .but she said come here and called me into her bedroom. It smelled like my Dad. . .A LOT. . .like almost overwhelmingly. He worked in the yard a lot and wasn't a big user of deo, if you KWIM. It totally smelled just like him.
Another one with smell. My ex DH's father died when my ex was 15. He was a one-match-a-day kind of chain smoker. Shortly after we moved into our house ex's Mom brought my ex things that belonged to his Dad (they divorced when ex was a baby and she had been saving those things to give him someday.) They are things like his dog tags, pictures, etc. We had stored them in a closet and sometimes it would just reek of cigarette smoke. . .and it was totally random. . .sometimes it smelled and sometimes it didn't. So weird!
Finally, my aunt's house is haunted. The ghost stays upstairs, mostly in what was my cousins' room. It moves the dresser and you can hear it walking around up there. I've never heard it, but her family has many times (she has 8 kids). Last time my Mom visited she slept up there (it's a spare room now) and she only lasted one night! She said she kept hearing somebody walking around in the room while she was trying to sleep, would get up and turn on the light and nobody was there. She stayed downstairs on the couch after that.

There is also the infamous family picture. All the cousins were home for one of my cousin's weddings. They gathered at the front of the house to take a family picture and in the picture you can see a shadow of a man in the upstairs window.