Dirt in an electrical connection? (5)

I believe the answer is:

earth

I believe this clue is a double definition.

'dirt' is the first definition.
(I've seen this before)

'an electrical connection?' is the second definition.
(I've seen this before)

'in' is the link.

(Other definitions for earth that I've seen before include "Connection between an electrical device and conductor" , "Heart (anag)" , "Soil; planet" , "costs so much?" , "our home" .)

I've seen this clue in the Evening Standard.

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