Green’s Dictionary of Slang

(US) a seat; 1931 refers to the electric chair.

1929		S.F. Examiner 4 Feb. 16/6: The way to lick Stribling, as I see it from my comfortable squativoo at the ringside is to [etc].
1931		D. Runyon ‘Romance in the Roaring Forties’ in Runyon on Broadway (1954) 41: I once see two guys go to the old warm squativoo up in Sing Sing.