Ontario condo light installation
The crossbar and the cut yellow wire suggest that a lamp was previously installed there.

It is OK to install a lamp yourself but to comply with code you must call a licensed electrician to inspect your work. I can see from the picture that the ground (green bundle) is being used as a neutral connection (white wires) and the end of the yellow wire is just floating, so even if you do nothing you will need an electrician to make it safe.