Personally, I'd just decide it's my shop mascot and leave it alone unless it started causing a problem as long as I was positive it wasn't venomous. I like snakes though. They fascinate me. I love to just watch them move around.
And like spiders, I like them a lot better than what they eat so like the man said, better the snake in the shop than its food.
If it starts making lots of babies there won't be enough food for all of them and they'll move along on their own.
I don't have any tips for getting rid of it. I'd start by using my friends at the Googles to see what I could turn up that way. Maybe if there's a switch plate or power outlet you could take off the cover and spray something in there that the snake wouldn't like too much - something stinky but not deadly that won't harm the walls and that might drive him out.
If nothing already there then drill a small hole to spray through and see if that works. If no joy then call an exterminator and see if they'll give you free phone advice.