First time I've heard the term "slap house" -- refers to an illegal gambling operation run out of a home. This one occurred in Anaheim. (Home of Disneyland -- California says still too "dangerous" to open Disneyland, but the slap house operates just fine!

Note the police raid was conducted at 8 am. They must have been playing all night!!

https://abc7.com/slaphouse-what-is-a-slap-house-illegal-gambling/7005291/