Electrician strangely cut and capped hot wire of receptacle
A long shot, but maybe:

Hot wire broke
Instead of fixing it, someone swapped hot &amp; neutral elsewhere and then for the neutral (not hot since they were swapped earlier in the chain) tied it to ground (which to a simple tester will look the same)
Latest electrician tried to fix the problem for you but due to the broken hot, couldn't easily fix it, and due to laziness and/or limited budget (i.e., he knows the landlord won't want to pay for many hours of extra work), he didn't fix it, just made it as safe as he could easily do.

The real fix depends on the type of wiring:
Cables

Remove the junction box and possibly cut holes in the wall for access
See if there is enough slack somewhere to use the existing wire and if that doesn't work...
Replace the entire section of cable (not fun), or
Use an approved in wall (i.e., hidden) splice to add an extension to replace the broken wire (not fun, but not as bad as running a new cable)

Conduit

Identify the other end of the broken wire and disconnect it
Pull out the broken wire
Put in a new wire

With conduit this should be easy. However there may be additional locations to be opened up along the path of the wire in order to get it all the way through. YMMV.