Address is listed as Wilson's Drive, just off Locust Pike, I think now called Wilson Ln.
Ralph E Caldwell Father 33
Jenevieve H Caldwell Mother 31
Joanne R Caldwell Sister 9
Judith N Caldwell Sister 8
Roger P Caldwell Brother 7
Neil R Caldwell Brother 6
"United States Census, 1940," database with images, FamilySearch (https://www.familysearch.org/ark:/61903/1:1:K7TL-4RB : 9 January 2021), Alan K Caldwell in household of Ralph E Caldwell, Magisterial District 6, Kenton, Kentucky, United States; citing enumeration district (ED) 59-73, sheet 22B, line 57, family 405, Sixteenth Census of the United States, 1940, NARA digital publication T627. Records of the Bureau of the Census, 1790 - 2007, RG 29. Washington, D.C.: National Archives and Records Administration, 2012, roll 1325.