Curious George at the Fire Station (Curious George New Adventures) by Margret Rey, H.A. Rey, Alan J. Shalleck (Editor)

This time George is in serious trouble. When he rings the bell on the fire engine, the firemen think there's a real fire. It seems that a fire station is no place for a curious monkey -- unless that monkey is George, who can do what none of the firemen can to make a quick rescue.