Depends on the wall construction and what the sparky felt inclined to fit.
If the wall is a partition wall and the sparky got in before the plasterboard was fitted he would normally use metal boxes (if he was doing a decent job). However if the walls were up before he got there then there's every chance he used plastic ones that grip onto the plasterboard.
Taylor Towers is built using that stuff in many of the internal walls.
Also uses those plastic back boxes with the clip on metal wings. Hate Hate Hate!!!
If you need to find a tradesperson to get your job done, please try our local search below,
or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Please select a service and enter a location to continue...
Are you a trade or supplier? You can create your listing free at DIYnot Local