LOL, it depends. If the Captain of the Poll is suspicious he can require an ID, and if there is no idea he can allow the voter to vote and the vote will not be counted until the signature at the Poll and the signature is compared and is the same or not.
However, when I first registered to vote, my signature was totally different to now, as to the number of signatures I signed on Warrants of Arrest and memo's to the bench.
As to dead people voting, that too is ridiculous. It is up to he counties for the Clerk's office to share death certificates to the county register of voters to remove their name.