Albus Dumbledore was (temporarily) a somewhat Dark wizard.
While he did “reform”, in his youth, Albus Dumbledore held ideology that was very much in line with what many Dark wizards believed. He believed that wizards should rule over Muggles - and was taking concrete steps with his then-friend Gellert Grindelwald to make that a reality. He sought domination over Muggles and to establish wizard rule, presumably with himself and Grindelwald as the rulers.
“Your point about wizard dominance being FOR THE MUGGLES’ OWN GOOD – this, I think, is the crucial point. Yes, we have been given power and, yes, that power gives us the right to rule, but it also gives us responsibilities over the ruled. We must stress this point, it will be the foundation stone upon which we build. Where we are opposed, as we surely will be, this must be the basis of all our counter-arguments. We seize control FOR THE GREATER GOOD. And from this it follows that where we meet resistance, we must use only the force that is necessary and no more.”
- Harry Potter and the Deathly Hallows, Chapter 18 (The Life and Lies of Albus Dumbledore)
He didn’t seem to enjoy the thought of killing, and he didn’t reach the Dark Lord or even Grindelwald in heights of deeds actually done before he changed his mind, but then, neither did Wormtail or most of the other Dark wizards we know of.
His ideology was nearly identical to Grindelwald’s, and as implied by his eventual chosen slogan, it’s entirely possible that Grindelwald also believed what he was doing was right. Dumbledore believed that what he was doing was right, yes, but many of the wizards considered Dark that we see throughout the series earnestly believed they were right. Grindelwald may have thought everything he did was “for the greater good”, but he’s still remembered by history as a very Dark wizard. So, at least for a time, Dumbledore could be considered a Dark wizard from Gryffindor.
There are likely more - we don’t know every Dark wizard’s house.
There are likely to have been several Dark wizards who attended Hogwarts since its founding, a time period spanning centuries, and we only see a small subset of those in the series. The characteristics of Gryffindor don’t eliminate the possibility of Dark wizards being sorted there - the main requirement is bravery, which isn’t exclusively a trait of “good”, though it is usually associated with it. The only quality the Sorting Hat mentioned as one favored by Gryffindor that tends toward “goodness” is chivalry. The most definitive Gryffindor trait, however, is bravery, which doesn’t eliminate the possibility of certain types of Dark wizards being suited for Gryffindor.
We don’t know the houses of even all the Dark wizards we do see as named characters in the series, mostly among the ranks of the Death Eaters. None of the ones we know of are known to be Gryffindors (other than Wormtail of course), but many are never mentioned as being in a specific house. Barty Crouch Jr., Yaxley, Macnair, and Rookwood are just some of the Death Eaters whose house is unknown and not hinted at.