On for me, which generally means propane, unless there are restrictions that prohibit it (such as some tunnels and bridges have). I do try to remember to turn it off before refueling (and on again afterwards).
While they are the cause of a not insignificant portion of RV fires, fridges are nowhere near as dangerous as some let on, not by a long shot. Engines, overheated brakes or tires, and electrical system failures also cause a good many RV fires, and people don't generally seem as afraid of driving, stopping, or plugging in.