@
swirlie Freemasonry has its roots in medieval stonemasonry. There were stonemason guilds who met together and they proved themselves qualified through secret signs, grips, and words. The secret signs, grips, and passwords we use today hark back to that. The details of the process are unclear but over time men who were not actual stonemasons joined these lodges and they developed into what we are today. In our ceremonies, we are presented with certain working tools used by actual stonemasons and it is said, "As we are not all operative Masons, but rather free and accepted or speculative, we apply these tools to our morals." We use the symbolism of building as an analogy for building our own characters.
As for the occupations of Freemasons, we have members from every walk of life. At a meeting I went to last weekend I met a young plumber. I have quite a few teachers or former teachers in my lodge, a guy involved in computer programming, a few guys in the film industry, and a bus driver. There is no reason why a member couldn't work somewhere like Walmart. The only requirements are that you are of good character, the right gender (depending on which order you're trying to join) and believe in a supreme being.