I have been working this in my House District since 2004 and we check the voter lists every election and sure enough some we had tossed like 35 people living in an apartment show back up. We thought ACORN had left this area but they reappeared in S. OKC and almost cost us a OK Senate race in 2008.
Several states the GOP Chairs in the State are asking precinct people to check their roles. It is a never ending job as they get taken off and then added back in but it gets faster after you initially check the list.
It is the only way I know to do it is to check each precinct. RNC Voter Vault is crap and that is being kind. Our State Election Board should have everything on computer disc but last we checked they were not operational (on purpose because a Republican only took over in January after we took the OK Senate).
RNC needs to get off the dime and put out something to all activists to check the voter list in their precinct. It is the most important item for RNC and the State Parties.