According to what I've been told by several people who have inquired of "practicing" (is that the right word?) Freemasons, and supported by Wikipedia, "Freemasonry explicitly and openly states that it is neither a religion nor a substitute for one. 'There is no separate Masonic God', nor a separate proper name for a deity in any branch of Freemasonry."
So for purposes of a fear of worshiping a false god, there should not be any prohibition.
But what about Darkeihem?
What about engaging of some foreign worship (ie., the rituals, ceremonies, etc., that praise G-d - even allowing one to identify G-d however he chooses/believes - are not Jewish rituals, ceremonies, etc.)?
What about using masonic symbols?