"A collection of insults 6" joke

Lights not burning too bright.

Like a barometer -- vacuum at the top.

Like a loose-leaf folder in winter.

Like a one-armed man climbing a rope.

Likes dunking for french fries.

Little red choo-choo's gone chugging' round the bend / jumped the track.

Lives in La-la-land.

Lives in the same world, but a different universe.

Living proof that nature does not abhor a vacuum.

Long on dry wall, short on studs.

Looking for a nickel in the corner of a circular room.

Looks for the "Any" key.

Loose chip on the microprocessor board.

Loose wire to his headset/ringer.

Low on thinking gas.