Ghosts of Fear Street #35: Horror Hotel Part 2: Ghost in the Guest Room (R.L. Stine)
Joe and grandpa switched bodies at the end of the last book. As they attempt to do a spell to switch back, grandpa disappears. Joe hears strange noises in the wall and thinks he might be in there. When he touches it though, weird good appears on his hands. His mom then wanders in and reminds him to put on his costume for the night. She tells him that if things don't go well, they might lose the hotel. When he finally gets ready, she asks him to go out and get some ice for the opening night party. Joe has no idea how to drive and almost causes a massive accident. He survives and does well at the party, only to wake in the middle of the night with the feeling that someone is trying to suffocate him. It's the goo again, which covers his face and slides down his throat. Joe tries to run away and runs into the wall. It becomes soft and lets him go through it. There he finds a bunch of webs covering every square inch as well as grandpa. Joe gets to him and fights off the web...