The following William Mailes is younger than your W.W. Mailes but the rest of his family seems to be in Maricopa Co, AZ in 1920. I couldn't find them in 1930 or Willim in 1920. The name as I'm sure you've found can be misread in a lot of ways. I've found it as Mailer, Mailen,, Mallen, etc.

1920 Maricopa Co, AZ census, Precinct 28, p. 17a
John F. Mailes m w 27 md TX AR IL barber? on farm
Pearl Mailes wife f w 27 md OK MO OK?
Chattie W. Mailes son m w 7 OK TX OK
Goldie M. Mailes dau f w 5 OK TX OK
Silvia B. Mailes dau f w 3y11m OK TX OK
John J. Mailes son m w 2y2m OK TX OK
Margaret J. Mailes mother f w 67 wid IL IRE TN
Minnie Mailes sister f w 28 TX AR IL

1910 Commanche Co, OK census, Lawton Twp., p.3a
William Mailes? head m w 29 US -- -- laborer
M.J. Mailes? mother f w 56? wid 7ch 7liv IL -- --
Minnie Mailes? sis f w 20 TX -- IL
Johnie Mailes? bro m w 19 md0y TX -- IL
Pearl Mailes? sis? f w 18 md0y OK MO --