He who suspekts everyboddy, should be watched by everyboddy.

[He who suspects everybody should be watched by everybody.]

Josh Billings (1818-1885) American humorist, aphorist [pseud. of Henry Wheeler Shaw]

Josh Billings’ Farmer’s Allminax, 1874-11 (1874 ed.)
    (Source)

See Johnson (1763).

In his 1879 Allminax (April), Billings provided a similar adage:

Whenever yu cum akrost a man who distrusts everyboddy, yu have found one whom it is safe for everyboddy to distrust.
 
[Whenever you come across a man who distrusts everybody, you have found one whom it is safe for everybody to distrust.]