Not all pinksheets and/or OTCs are "fake shells" but once you start to wander into sub penny territory there is a high likelihood that many are just as you described them. To find more "legitimate" microcaps you need to look for a higher PPS (assuming it is not the result of a reverse split) and also you need to scour pinksheets.com and look at for their "premium" label.
A few things to keep it mind when looking at the history of EVXA in particular in regards to its seemingly high PPS is the massive 500 to 1 unannounced (!) reverse split they held in March, as well as the fact that a little over a year ago EVXA was known as Cambridge Energy, an actual "legit" company.
Honestly, I think it will hit bottom again where it tested the last 2 times and rebound. I would not be surprised to see it go back to .004 and higher eventually. I would expect the company will release another PR before the end of year, this will most certainly have a positive effect on the pps. If that happens you will probably see penny land again. If they do actually get a contact then definitely you will see pennies, IMO.
News 
Market Data 
Discover 
