I’d like to be a mole on the wall

I wonder what they will say? I’d like to be a mole on the wall...

Kevin Keegan in a Football Commentary

A Mixed Idiom made up from

1. Fly on the wall, and
2. Mountain out of Molehill, or perhaps
3. Blind as a mole.

Source of this Mixed Idiom?

Sent in by Oliver. Thanks Oliver!!