The awnser could be very easy here;
IF it is a
STATIC OBJECT they can
NOT be enabled\disabled.
it sorta
CAN be done,
But i guess you are a beginner and i think you should work on the engine \ editor(s) a little first.
IF you want to know we can explane but you might not understand what we talk about.
About your WALL ; You can disable \ eneble 99% of the Entities,
so please try adding an entitie in stead of a STATIC OBJECT.
Hope we helped here.
For more questions, be free to ask them, That's why we are here
Good luck.