Assistant Technical Director at the Seattle Repertory Theatre here. I find lots of similarities between the work and this hobby. Many useful materials and tools definitely cross over. I used to be in a union position when I was the Scene Shop Foreman at Seattle Children's Theatre, that was with IATSE local 15 in Seattle, like Ken said the union around here is based in Seattle, although the jurisdiction covers just about the whole state and parts of Idaho I believe.
At one point I was a member of Local 488 which is the Pacific Northwest's film and television local for IATSE, that was when I worked on the movies Steven King's Rose Red and Paramount's The Hunted.
I've been behind the scenes since my sophomore year in high school about 13 years ago, I've acted a few times and enjoyed it, but I think my carpentry/design skills are a little more refined.
Right now the "Rep" is in our off season so I am working in a shop that builds museum displays and exhibit parts, we are working on some cases for the Museum of Flight, and Sci-fi museum here in Seattle, and in a week I will be headed out to do some work at the computer museum in Albuquerque, NM. The cabinets we build at this job are definitely good ways to learn some great techinques for arcade construction.