Could the “clicking” be from pullcords on the fan? In my old apartment, the fan had two cords (well, chains): one for the lighting in the center of the fan, and one on the side to control the fan speed. Sometimes the fan would get a little off-balance, which would lead to a wobble and cause the side chain to knock against the fan housing.
While the fan is running, check whether the cords display any movement, and if they’re hitting the casing.
You can try dusting the blades (this was usually my problem, and yes it says something about me that dust accumulation would get that bad) or some of the “wobble or movement” fixes on Dandmb50’s link. Worst case, you can put something on the casing or the pull cord to dull the noise.