Are you looking in right war?If I pulled up correct 1930 census there's a John Zingaro (wife Veronica, son Joseph).Census says WW veteran.US didn't enter WWII until 1941.
For some reason Ancestry.com won't cooperate & I can't pull up WWI Draft Reg. Card.There's also a WWII Draft Reg Card:
John W. Zingaro 4820 Umbria St., Phila Penn b Tareytown NY Nov 20, 1895 Emp:Phil. Fiber Box Board Mill, Delaware Ave & Tasker St., Phil.
WWII cards were filled out April 1942 for men born on or after April 28, 1877 & on or before Feb 16, 1897.
BTW, have a Draft Registration Card (WWI or WWII) does not mean one was in the service or drafted.Only means they registered as required by law.
Also, next family down on 1930 census is a Michael Zingaro (wife Mary, 4 kids); census says he's a WW veteran.
Family directly above John is Anthony Patrella )wife Rose, 3 kids).Anthony Patrella is also a WW veteran.Listed with family is Rose's parents, Dominick & Josephine Zingaro.
You can order service records from NARA but you'll need to know branch of service, rank (or at least whether enlisted or officer), date(s) of service.Comm. of PA has info on their website about many veterans; should check there.It's possible Philadelphia has something in its archives (don't know anything about Phil.-never researched there).