If he has absolutely no connection to the actual Ralph except they have similar powers, he's fake. Just like Fake Atom Smasher, Fake Doctor Light, Fake Jesse Quick, etc. The real Ralph Dibny was never a police detective, he sure as fuck was never corrupt, and he got his powers from a special fruit extract, not a shitty character that stole The Thinker's name. There are no real similarities between TV Ralph and real Ralph except that they stretch. Hell, the real Ralph only had shapeshifting powers in one shitty comic (Gail Simone's New 52 Secret Six book) and thats pretty much it, so really TV Ralph is actually more like Plastic Man then he is Elongated Man. Hell, they're also both former criminals. Give Fake Ralph a red suit and he is just Plastic Man (but a lot less entertaining)
If they aren't the comics character, then they're a shitty OC of the show's writers that stole the name, and as much as I enjoy The Flash when its good, the show pulls that bullshit way too much. So does the entire DC CW universe actually, but if I start thinking about the fake Legion of Superheroes characters or the Fake JSA I will literally just start frothing with anger and write a damn essay so I'm not going to go down that road.