The room we are in varies in humidity throughout the year. The clicking and popping only appears in the winter when it is very dry. It also only appears near the end of a long recording session, after about 2 hours. We are using a. Earthworks FM360 lectern microphone. We have replaced the microphone (with an identical microphone from the same company) several times. Also, in our case the clicks and pops appear suddenly near the 2 hour and 15 minute mark, although the timeframe is not exact.
Actually not entirely suddenly. After about 2 hours we start to pick up an ocassional fuzzy radio static like sound. Then at a certain Point–SNAP! Very loud. Once you get one pop you will be sure to hear a second in about 3 minutes. The only thing the stops the repeated popping is swapping out the microphones but it will come back two hours later.
It only gets that bad on maybe 4 or 5 weekends each year but its drastically bad when it does. This has been consistent for 5 years now although a little extra dryness has been bringing it into the spring this year. Probably the 5th microphone too.