Yes for modules with code wheels if the board is out of the case and not contacting the code switches. M13 is the code. That is what I use when testing modules out of the cases....
You often take them out of the case to test them?
...That said playing with open modules with line voltage derived power supplies can be an explosive experience if the wrong thing is touched or grounded.
Most definitely could be a shocking experience.
This is one reason I have a GFI on my X10 test box.
I demonstrated how a GFI worked one day to my 13 year old by shorting the live wire to an external ground. (Should of done it through a load.) She enjoyed the sparks and wanted me to do it again. Oh well so much for setting a good example.
Ok Boys & Girls don't do this at home. We're professionals that need a little jolt to get going from time to time.