"a few sandwiches short of a picnic"

[Nanodick]

tio suan just now but i learn a new phrase
nevermind, every dog will have his day for revenge

 

[Nanodick]

https://en.m.wiktionary.org/wiki/few_sandwiches_short_of_a_picnic

A few sandwiches short of a picnic

1. (idiomatic) Exhibiting disquiet or unsoundness of mind; not sane; mad. synonym ▲quotations ▼Synonyms: see Thesaurus:insane
2. I think the lady down the road is a few sandwiches short of a picnic—you often hear strange bangings at odd hours in the morning.

 

[bobby]

Same as saying the lights are on but there is no one home.

 

[Boonsiong]

Hokkien also has similar phrase called

Lanjiao moh pak si kat
阴毛打死结