Green’s Dictionary of Slang

(US) a psychiatric institution.

1959		Life 23 Nov. 45: If a disk jockey had to listen to all these records, he’d go to the kookie house [HDAS].
2002		‘Vinyl Boy’ Crackerbox.net 🌐 Rev. of Forest for the Trees: His friends told him that he had a problem, so Carl admitted himself to a phsyciatric institute (kooky house). He calls this his ‘dark period’.