Found him on the 1900 Brooklyn Ward 19, Kings, New York census (dist 297 img 29) as Fred A. Finger
age 4 months.
Found him on the 1920 Brooklyn Assembly District 2, Kings, New York census (dist 95 img 70) as Frederick Finger
age 19, living in the household of his brother Charles
WWII Draft Registration
Found him on the 1940 New York, Queens, New York census (dist 41-778 img 21) as Frederick Finger
age 40, married. He is in the Creedmoor State hospital