On my 2008 Starcraft 14 R/T model the ceiling kill switch is a plunger switch in the top of the cabinet that houses the fold over Stove Top and Sink portion when you fold over to get ready for transport. This is a safety feature for making sure the 12VDC Light Fixtures will not come 'ON' when the top is lowered for transport. This only shuts off the ceiling lights in my trailer.
Mine looks something like this one from Google Images
This was designed for the ceiling lights that uses the very hot 12VDC incandescent automotive bulbs. Since everyone is beginning to change out all of these older very hot bulbs for cool to touch LED panels this feature may not be necessary to have anymore...
My original battery battery setup had an in-line fuse holder just inches away formthe battery to protect the battery cables in case of a short to frame ground. A standard Battery can produce 100s of DC AMPS if it sees a a frame ground short. Could start a fire burning up the battery battery cable...
My original IN-LINE FUSE looked something like this... Mounted within inches of the Positive Battery Terminal..