Why am I getting shocked when my breaker and switch is off?
Might be this. 

This is called a multi-wire branch circuit, common on US split-phase though it can occur on any multi-phase-with-neutral service.  Multiple phases or poles share a neutral, the neutral carries only differential current. 



It has special rules and you see why. 


Neutrals must be pigtailed, for the same reason as grounds - removing a device must not interrupt the neutral wire for other legs of the MWBC.  
The breakers must be handle tied -- the issue is not common trip (overcurrent on one leg is no reason to shut off the other leg) -- but rather, to assure maintenance shut-off will shut off all legs. Even with neutrals pigtailed, a fault in the neutral wire will cause any leg to energize all other legs.