Okay so... I've been helping to edit and kinda moderate a wiki for a while now with one other person, but neither of us are admins. We've also had no luck getting ahold of the wiki's admin and in their absence, it seems as though every other day, we've had to clear up graffiti or rude messages.
So my questions are
What we do about the absentee admin and how can we become admins?
Is there a way to block/ban the people causing problems throughout the wiki?