It concerns me gravely when someone accuses a professional electrician of purportedly sub-standard work. I have friends and relatives in the trade and what they have all conveyed to me at some time or another is that from day-one of their training, they have had two things drilled into them. The first is that there is no room for errors - as people’s lives are at stake, including their own. The second is that there is no such thing as a “shortcut” when it comes to electrical wiring and fittings.
So your comments raise some serious questions and concerns for me. Did you employ and pay a practising electrician? Are you certain that the wire used by the electrician was exactly same as that in the photos displayed? Did the electrician advise you about limits to the wattages that were safe to use in the outlets provided? Have you since had any problems or perceptible degradation with the work that was done?
Problems can and do arise when people that are not fully qualified do their own wiring. For example, a lack of understanding of things such as ‘current draw’ due to wattages of appliances and the corresponding heating effects related to this can result in overheating of electrical wiring, especially where the external insulating sheath has been removed. Another is the heat production of the various appliances being utilised and whether or not this heat will likely be readily dissipated.
For example, the hard plastic sockets in ceiling lights are acceptable for incandescent globes up to 100W, where there is no enclosure of a light fitting. The airflow around an exposed ceiling fitting provides adequate cooling to eliminate any chance of a fire. Put the same light into an enclosed fitting or use a higher wattage and it is a different story. In such cases a non-flammable ceramic fitting is then required. Along the same lines, down-light fittings don’t have the same air flow around them that exposed sockets do and so have a totally different set of criteria that apply.
Applying this to reptile enclosures, the often reduced airflow around high wattage bulbs utilised requires someone with the appropriate understandings and knowledge to set it up safely. Something the DIY person copying light fittings in the home may not be capable of doing. While experienced keepers likely have the ken required, the majority of newer keepers would be well advised to seek the advice and approval, if not the full services, of a qualified practising electrician in my opinion.