We lived in Scottsdale, Arizona, in the early 70s and didn't find scorpions to be a major issue. It might be different out in the open desert.
You quickly learn to check your shoes before sticking your feet into them and to shake out things that are on the floor or otherwise accessible to the critters. (Those things probably shouldn't be on the floor anyway). We're outdoor folks and never found huge infestations of scorpions anywhere we went. Now, if you are into turning over rocks and logs, you might find more of them than we did.
My take on the black light is that it may just make you feel less secure rather than more. If you are constantly looking for scorpions, you will probably find them. There are all kinds of critters in this world that can be potentially hazardous; snakes, spiders, bees and wasps, scorpions and all the rest. If you feel the need to equip yourself against all contact with any of them, you will be loaded down to the point where you won't be able to move.
Just use a little common sense and keep your eyes open. Learn about habitats that support these critters and do your best to avoid or eliminate them.
TJ
