The Dimensional Shift. Shift Happens, #1

Chloe Watson is an ordinary girl looking forward to a nice, peaceful winter, until she finds a bizarre artifact in a hotel room and meets its owner, Andrew Paige. He might look like an ordinary suit, but he's got a string of secrets hiding behind his knee-weakening smile. When he offers her a job at The Dimensional Shift, Chloe is tossed straight into the world of inter-dimensional tourists and their odd accommodations.
Between dealing with the Shift's unusual guests, and trying to determine if the boss' interest in her is strictly professional, Chloe uncovers a plot to steal the hotel's dimensional keys. With the help of the town gossip, her alien abductee neighbor, and her new invisible best friend, Chloe confronts and inter-dimensional crime ring and a host of complications that make romancing the bosslook like the leastof her problems.