horror, siblings who are talking to another kid and find out that he's a ghost

[Kalee]

My cousin gave me the book years ago when I was a kid. It was probably out in the 90's. The cover had this green monster/ghost thing with glowing yellow eyes and a sinister grin. I can't remember much about it, but basically this kid with his sister i think, move somewhere new and they meet another kid. The house they moved into has a history where it burned down and killed two other kids. The new kid they meet seems a bit strange and takes them to see his school and they realize that everything is old fashioned at this school.

***SPOILERS***
They find out that he was a ghost who's abusive father forced him to burn his friends (who were also siblings, but i'm not sure) alive in the basement. He's in the process of burning them alive in the very same basement, and i can't remember if his father as a ghost is terrorizing him again, but i don't think so. I don't remember how it ends, but pretty sure they escape.

[Rainbowheart]

The Ghost Next Door?