48 Pa. C.S. § 1321
If a hotelkeeper or campground owner posts in a conspicuous place notice requiring the guest or boarder to secure the room, campground-owned lodging occupied by the guest or boarder or other personal property, or, in leaving the room, campground-owned lodging or personal property to secure the property and to deposit the key with the hotelkeeper, campground owner or the clerk at the office, the hotelkeeper or campground owner shall not be liable for any baggage or personal property of the guest or boarder which may be stolen from the room, or campground-owned lodging if the guest or boarder shall neglect to do so. In order to avoid liability, the hotelkeeper or campground owner must clearly establish the fact of the room or campground-owned lodging having been left unbolted or unlocked by the guest or boarder at the time of the loss of the baggage.
48 Pa.C.S. § 1321