What is the solution to this problem: The Risk of “Faithless Electors?”
Really, it is hard to say that "faithless electors" are a problem because they are so rare and have never made a difference. There was one faithless elector in 1988 (that person flipped Michael Dukakis and Lloyd Bentsen, putting Bentsen for President even though he was the VP candidate) and one in 1976 (I don't think there were any in between). Neither of them made a difference and there hasn't been one since.
According to the link I am attaching, the best solution to this "problem" is to just have an automatic awarding of votes rather than any actual electors. We would need to amend the Constitution to say that each state's electoral votes would automatically go to whoever won its popular vote.