I'm completely clueless what the cable is (and a lot of other things
). It's odd that it's a 3+1 pair construction which is probably quite difficult to manufacture accidentally. I think it's going to be a question of asking the electrician to go contact the wholesaler and find out what it's for. I've searched all over the interweb thingy and not found anything close.
Update: It looks like it's USB 3.0 cable which has three data pairs and one (thicker) power pair. I have found a similar cable here but not the exact equivalent.
I’m not really sure your weird cable is the same as the USB3 cable! That cable you linked to has 3 individually screened pairs and 2 larger gauge cores (not a pair) as a power “pair” all within an overall braid/screen for the cable. It is actually more like a Cat 7 cable (or the old IBM Type 1 cable) in this respect with individually screened twisted pairs and and overall shield.
Now if your cable is not a “structured” cable - I have bit my to tongue in the description of it an “Ethernet” cable here

as Ethernet is one of the many protocols, but admittedly probably if not the most popular data protocol, to run on 100-ohm 4-pair (unshielded/shielded) twisted pair - that is its not Category/Class rated UTP/STP structured cable and something else like a specific USB cable then that’s going to have a different characteristic impedance.
One thing that is common across all generations of Category 3, 5, 5E, 6, 6A and even 7 cable is that their characteristic impedance is 100 ohms. Probably not a well known fact but quite important in the grand scheme of things. Other twisted pair cables and there are literally thousands of types may have a different characteristic impedance - hooking that up a cable that has nominal 90 ohm characteristic impedance for example to (Ethernet) gear that’s expecting to see nominal 100 ohm impedance *could* result in signal reflections, especially towards the upper end of the frequency range that GigE works on.