I may be completely wrong but I have identified this as a Marbled Gecko (Christinus marmoratus). It is a species of Gekkonidae (gecko) native to southern mainland of Australia, from Victoria to Western Australia. 

The species is well adapted to a variety of habitats, including city dwellings. 

This one was about 70-80 mm (about 3 inches) long including its tail.

We first saw it lying in the mortar line of the brickwork on the front of our house. When it was startled by us it fled into the space between the front door and the bricks.

It re-appeared behind a ceramic wall hanging in our front entry.

The images inside are made where it was lying in the gap between the door sill and the tiles.

I have returned it to the garden but it seemed keen to head back to the house, so it may appear inside again.