Not finished walls in electrical room
Yes, the gaps are a “Fire Code” issue, ( in the U.S., anyway...I don’t know about Canada, but I suspect it’s similar.)

You indicate your building is 3 stories plus a basement. In the U.S., this requires “Fire Resistant” construction, unless there are automatic fire sprinklers throughout the building. 

What this means is that gypsum board must be on each side of each wall to protect the structural framework of the building. They call this a “1-hour Fire rating”. Without this gypsum board covering the building is “non-rated construction” and the building is limited to 2 stories. 

Gaps in the gypsum board covering is of utmost concern in the electrical room where a fire is of extreme importance. 

I would notify my HOA or building management services of this concern. If they do not take action, I’d notify your local Building Official of your concern. 

I doubt the gaps are creating a smell into your unit. There may be a broken sewerline in the wall that allows a smell to seep into your unit. If you cal “rattle” pipes, that would be an indication that pipes are loose, broken, etc. 

Another option to your smell situation could be that a vent below you is tied into your sewerline allowing the smell to seep into your unit through the plumbing vents. You’ll need access to the lower units and a smart plumber to figure that one out.