Raul no this is not a standard practice and is most likely the result of improper installation of electrical attic wiring.
Running wires through your attic.
Find your attic access.
If you can run it across by stapling it to the rafters you can avoid the insulation thing.
You simply mount a small plastic clip to every other joist.
Yes this should be corrected and it would be good to have the wiring and all the circuit connections inspected as well.
When running along the joists keep them 2 above the ceiling.
Although it s rarely a problem in an accessible basement or attic if your home is built over a crawlspace or has a low narrow attic it can be hard to find the hole you ve drilled in the wall plate.
How to run wire through an attic step 1.
Where the cables can t be walked on.
This is usually a moveable piece of drywall or plywood that covers a rectangular hole in.
Measure the distance between the two sites you want to run wire between and make sure you will have enough wire.
As nickblake says run cables on top of ceiling joists but route in a low part of the loft i e.
Do not drill them through the joists or rafters.
The attic wiring should be protected and secured to ceiling joists or other wood structural supports.
If a lot of wires are already hanging from the bottom of the floor joists you can run the wires through raceways that fasten to the bottom of the joists.
Quickly fishing wires from the attic.
After you窶况e run the wires through the clips you snap a plastic cover over the entire assembly.
Even you are the first time to run security camera cabling you can install your security camera wiring through attics walls for your front back door reception room front back yard shop floor bedroom garage warehouse basement parking lot farm entrance even upstairs etc.