I own two businesses - one that does electronic security and works with GCs / construction weekly. I can't tell you how often we have to deal with shoddy door frame builders and millwork companies (esp millwork). The GCs can't seem to get good ones and throw up their hands with exasperation - I've had this experience in OH, VA, MD, and PA. It's project based, but once you get a good rep, you'll be passed around and carried from company to company. It's upstream from us and I have my hands full now, otherwise I would do it myself!