switched earth inside fuse box

hi looking to install a dash-cam and want a switched earth , I have tried the fuse box in the passenger side foot well but they are all permanent live does anyone one have a suggestion for the drivers side fuse box to save me searching with a circuit tester .

cheers

Do you mean a switched live? So when you put the ignition on, it comes on.

err yes sorry for the confusion :blush:

Easiest way i found is connecting it to the cigarette lighter fuse using a fuse tap.
Something like this
http://www.ebay.co.uk/itm/291250191480