Rewiring 4 security lights & install light in shed Completed

We installed 4 security lights 2002. This was done by a DYI electrican friend. 2006 we got an arlam system installed, Aug 2009 we got and HRV system installed and Oct 2009govt installation of Bink bats all in the roof cavitiy. And now the security lights do not work since Aug 2009. My cousin went to have a look and said that the orginal wiring for the lights is looking really bad and the wiring for the lights need replacing. As it is a risk for the house insurance. Also we built a tool shed Mar 2009 and would like to have a light in the shed. I have bought the wire and a switch for the shed's light but need an expert to put this all in. So with this job I would require a electric certificate of complaince.