In an interview Tuesday on CNBC's "Squawk on the Street," Fisher said, "It's sort of a choice between quicksand and a bullet in the head."
Fisher wouldn't say which candidate he considered the "quicksand" and which one he considered the "bullet."
"I'm not going to tell you. You guess for yourself," he said.
"I don't think I have much of a choice here," he added, jokingly saying, "I'm supporting Alfred E. Neuman," referring to the fictitious mascot of Mad magazine.
Fisher, known for his contrarian and often provocative views, was head of the Dallas Fed for a decade before retiring in 2015.