The network point in the wall is simply an extension to a network port on the main switch or router.
Normally these wall points are linked to a patch panel, which in turn will be connected to a router / switch.
If this point is not live then it mustn't be connected to the switch/router.
Now if the person who installed the network was organised, and nobody has messed things up since the wall point should be numbered, and this should match to a corresponding port on the patch panel.
now your job is to work out where the wall point should be connected to...