The safest approach is to assume that ‘no commercial use’ means not usable for anything other than pretty decorations on your own system…
But, often times that isn’t the case, especially on ShareCG. The basic categories for usage rights aren’t detailed enough. Your best bet is to actually look at the read-me. I’ve seen things labeled ‘no commercial use’ that go from absolutely not to yeah, but you have to give me credit. And redistribution is always a ‘not in this life time’ if it isn’t specifically spelled out, in the read me, that it is allowed.
Some of the other things I’ve seen under the noncomm…you can pretty much do what you want with the prop/item, but you can’t make and sell any derivatives or add-ons; renders are fine, but if sold/posted links need to be provided and so on.
Also when you are talking about ‘fan items’ (Trek, Dr. Who and what not) and celeb ‘clones’ there’s another whole set of rules to go by…like contests are fine for most fan stuff, but don’t try to sell anything.
S0, I’ll say it again…the best, most accurate source for usage information should be in the read me. If not and there’s no easy way to contact the creator then fall back to the category listed in the description.