If you start off as an electrician, you don't have to remain an electrician forever. You can move up to managing other electricians. You can become a general contractor and manage multiple trades. You can become a real estate developer and manage your own custom or spec builds. Welding, electric, plumbing, roofing - that's just the skill you start with, but entrepreneurship in these fields is alive and well, and the sky's the limit for ambitious people.