The phrase "set on fire" can be replaced with a range of synonyms to convey the same meaning, but with varying degrees of intensity or emotion. For instance, one may use the verb "ignite" to describe a deliberate act of lighting a fire, whereas "kindle" suggests a gentler process of starting a flame. Other synonyms include "incinerate", which implies complete combustion resulting in ash, or "torch" which connotes a destructive or violent act of setting something aflame. "Scorch" may describe a superficial burning without causing complete destruction, while "burn up" emphasizes the intensity and speed of the fire. Ultimately, the choice of synonym depends on the desired effect and context of the sentence.