If it is the Sedgewick Hotel you would like to visit, you are out of luck. The place where the Ghostbusters first encounter Slimer, does not exist under that name. The hotel that was used for the film is actualy the “Biltmore Hotel” at South Grand Avenue. Good luck hunting down the Slimer ghost!
http://www.millenniumhotels.com/usa/millenniumbiltmorelosangeles/