Not the sharpest tool in the shed.

A few fries short of a happy meal.

The gates are down and the lights are on, but the train ain't coming.

All foam no beer.

The lights are on, but nobody's home

A few beers short of a six-pack

The wheel is spinning, but the hamster is dead

A few screws short of a hardware store

About as sharp as a marble 

 

A sandwich short of a picnic

A few bricks short of a full load

Not the full quid

Not the brightest light on the Christmas tree

The elevator does not go to the top floor

A few cards short of a full deck

Not the sharpest knife in the draw

Hasn't seen the ball since kickoff

A few fuses short of a full circuit

Thick as two planks of wood

A few clowns short of a circus 

No grain in the silo 

Forgot to pay their brain bill

As bright as a blackout

The battery is not fully charged

Would lose a debate with a doorknob

 

A few snags short of a barbie.                  Not the sharpest pencil in the case.

Dimmer than the inside of a coffin.          Too much yardage between the goal posts.

 

Couldn't pour water out a boot with the instructions on the heel.

Fire is burning, but the chimney is clogged.

Has mostly air between the ears.

In the pinball of life, his/her flippers were a little further apart than most.

A few spanners short of a tool box

Not the full bottle

A couple of ribs short of a cage

The bouncy castle has a hole in it

Table for four, but two chairs missing 

The phone's connected, but there's no dial tone

 

Not the crispest shirt in the closet

 

Their dog teaches them new tricks

 

If brains were electricity, they wouldn't have enough to light a firefly 

Quite fitting really for both RLC and VHTV. 

Not the brightest light in the harbour

An intellect rivaled only by garden tools

Another brain would be lonely 

Not the quickest horse in the stable

If their nose was on upside down they'd drown in the rain 

Somewhere there's a village missing it's idiot.   A few colours short of a rainbow.

Their banjo is short a few strings.                        So dense, light bends around them.

Biscuits aren't quite baked.                                    Not the most absorbent sponge in the sink.