I put in a gazebo in the back of the house and I want to install a receptacle from the only electrical source which is a porch light. I could just run some wire thru the base of the light and run it to the receptacle but it looks very cheesy. Is there a type of box or extender I could use to make up to code and look like it was done right
You can add a box extension with knockouts, then run conduit down to a box with a WR weather resistant GFCI. If the cover or roof of the gazebo protects the location from rain a standard cover can be used but if it is wet your will need a hard use or in use cover (and the box itself will need to be listed for wet locations). Some folks don't like surface mount conduit if this is you you can box the conduit in. I have seen some very artistic "cover up's of conduit that made it look like a grape vine at first I did not realise it was conduit as they were on several posts.