It's probably a kinda safe way to get on the building while avoiding security cameras, but I have no clue how they arrived here. Flew with a hang-glider from the Falcon institute next door or some crazy shit like that maybe; anyway they captured two electricians and took their clothes; they didn't need some of their stuff like the electrical tape so they used it to restrain them.
There's no problem, they didn't leave an electrical hazard hanging or anything; the dudes had already long finished their job and were taking a few hours long break because they get paid by number of hours worked. Well on the plus side they might get paid for a nightshift now.

Not sure how far electrician clothing can get them tho. Meh, they can change at some point or just go into hiding.