I don't remember much because I watched it years ago as a child but I think it might have been from the late 80's or 90's and there were these two kids (boy and girl maybe in their early teens). I remember there being a death (that they were trying to solve maybe?) and at the end of the movie it showed a flashback to the woman's death that they were trying to solve and it was shown that she was driving a car (it might have been raining) and she swerved to avoid a deer and crashed and died. I think that up until that point it might have been thought she was murdered. I know the movie was about a ghost (the woman's ghost I think) or multiple ghosts and at the end the kids were in an old barn or something similar talking about how now that it was solved they didn't have to worry about ghosts anymore and then all the windows of the barn slammed shut.
Sorry it's so vague, I watched it when I was a lot younger and don't remember very much.