While eight states do not allow write-in votes in federal elections, in Texas anyone eligible can file as an official write-in candidate. They only need to get the signatures of 38 individuals to serve as presidential electors, individuals who would cast votes in the Electoral College should they win a majority of the popular vote in Texas. This process saves the candidate from needing the 80,778 signatures required to make it on the ballot. The certification process assures that candidates who are ineligible — or do not exist — cannot be counted during vote tallying.
I believe I read somewhere Earlier that the Cruz Campaign must act on this before Late August, If it wants the Votes to be counted at all.
Somehow I just don't see him doing this in Texas or any other State (which some don't allow at all and have different deadlines).