Has anybody ever got a background check from Taiwan?
Did you get it in person or from outside of Taiwan?
How did you get it? What is the easiest way to obtain one? (I am trying to get it done all through mail or online since I currently live outside of Taiwan.)
Have you asked your local TECO?
Local police station in Taiwan.
Can apply online here and then pick it up 3 days later from the police station that you click on in the drop down menu (if you are in Taiwan)
Or you can go to your city’s police department and get it in the same day (it usually takes one hour) if you can’t wait 3 days.
Hello LTGR, and welcome! 
It depends on where you live (inside or outside Taiwan). If you search for “criminal record check” or similar phrases, you can find our previous discussions of the issue.