R.L. Stine 
Nightmare Room #7: The Howler [EPUB ebook] 

You hold in your hand the key to a shadow world of shivers and screams. Take a step away from the safe, comfortable world you know. Unlock the door to terror. There’s always room for one more in…The Nightmare Room.Spencer Turner is a major electronics geek, and he’s just purchased a cool new gadget called The Howler. It’s supposed to allow Spencer to pick up the howls of ghosts and spirits. Spencer would love to communicate with the spirit world. He can’t wait to see if it works. Unfortunately, Spencer soon hears his own howls of horror — because when he turns on The Howler, he opens a channel to The Nightmare Room.What will you find in The Nightmare Room next time? Check out book 8: Shadow Girl.