I'm not sure where to post this. I guess these feelings/fears are coming from being abused as a child.

Anyway, I live in a row home. Next door to me lives a woman, a drunken husband and 3 small children. 2 boys and 1 girl.

The girl's bedroom is in the back, next door to the room where I sleep. Almost every Thursday night-I hear her scream. About 3 oclock in the morning. Sometimes I'll hear the door close before hand or after the scream. Sometimes it's a couple of screams. I'm scared for her.
Like I said, the father is a total drunk. Eyes always blood shot to hell and staggering and slurring his words. I find him passed out on my front steps some mornings if the mother hasn't already kicked him off of them.

My bio-father was a drunk and when he was he was abusive to us kids. He also molested us.

So, I'm woken up by her screams and I keep reassuring myself that she just had a bad dream or something but my stomache churns thinking "What if..."
Do you think I'm over reacting? Do you think I should investigate and if you do-how?
I can't call the cops 'cause I don't know what's going on. Her mother scares me. She's very loud and won't hesitate to yell, curse or make a scene if, God forbid, I had the nerve to talk to her about it. So, that's out of the question.
What would you do? Should I put a glass to the wall and listen more carefully to see what's going on?
I dont' know what to do.
Please, any suggestions.