The phrase "where there's smoke, there's fire" can be used to indicate that there is often some truth to rumors or suspicions. There are a number of synonyms that convey a similar sentiment, including "there's no smoke without fire," "where there is suspicion, there is also truth," and "if the shoe fits, wear it." Each one suggests that if there is any indication of something, there is likely some truth to it. Other similar phrases include "a grain of truth," "a kernel of truth," and "a nugget of truth." These all hint at the idea that even if something seems small or insignificant, there may be more to it than meets the eye.