I have such a chip in my collection, also. Hope I didn't take a bath on it.

There are references to this being a short-lived card room (1968) in Mission Beach.

http://www.ebay.com/itm/OLD-VINTAGE-1968-CALIF-CARD-ROOM-CHIP-BATHHOUSE-37-MISSION-BEACH-CA-/121588612509

Mission Beach Bathhouse is in the National Register of Historic Places:

http://pdfhost.focus.nps.gov/docs/NHLS/Text/78000753.pdf

See also Item # 50 on 100 Lost Buildings of San Diego, where it's described as a casino:

http://www.sohosandiego.org/reflections/2006-2/100lostbuildings.htm

In all likelihood, Bathhouse 37 if it existed as a casino, was an illegal operation.