Abstain From the Appearance of Evil is a myth because that is not a translation of the Greek New Testament or of the Vulgate. Both of those agree with the following:

1 Thessalonians 5:19. You must habitually not ever quench the Spirit, 20. you must continually not ever despise prophecy, 21. but you must constantly prove all things; you must incessantly hold fast the good, 22. you must faithfully keep yourselves away from every form of evil.

Keeping away from every form of evil is very different from abstaining from the appearance of evil. Abstaining from the appearance of evil has two meanings: One is to not do anything that might even appear to be evil, even if it is innocent and permitted; the other is that you can do something evil as long as it does not appear to be evil.

Keeping away from every form of evil means to be above reproach in whatever you would do or say.