There are numerous synonyms for the phrase "set light to something." Some of these synonyms include "ignite," "kindle," "light," "spark," "fire up," "torch," "inflame," and "burn." These terms are often used in the context of intentionally starting a fire or causing something to burn. Moreover, they can be used interchangeably in various situations, such as lighting a candle or starting a campfire. While each of these terms has a slightly different connotation, they all refer to the act of igniting something with a flame or heat source, often with the intention of causing it to burn.