Ghosts... in my house???

I don't believe in ghosts. Never have. I believe that they are the wonderful stuff of stories and I welcome them in the books I read. 

Until we moved into our new house. It's not that old, the house. It was built in 1972, doesn't seem ancient enough for ghosts, does it? We bought it from the original owners, after the death of the father. 

To my knowledge, no one died in the house, either. So there should be no reason to feel haunted. And yet... 

There is this hall closet door that keeps being opened. At first it was irritating. "Why is that door open again?" That kind of thing. 

I've figured it was my child or my husband, and I'd close the door and carefully latch it, wiggling it to make sure it's actually shut. 

Then last night, when my son was in bed I went in to the bathroom and when I came out the closet door was opened. I KNOW it was closed before. My husband hadn't moved from the couch, he was working on his laptop. 

How did that door open itself up? How, how, how??? Now I admit to being extremely freaked out. All over a closet door.