I do believe in ghost though I havent seen one, but just based on those people who are closed to me whom you can really sense that they've seen something unusual through their facial expressions, but anyways, for me GHOST is not the main issue here, but FORGIVENESS, forgiveness from her EX and forgiveness for himself... anyways, I'm not really sure about forgiveness from her EX since she commited suicide (based on church's teachings, peeps who commited suicide cant go to heaven), and God also said, let the dead bury themselves... for me its only HIM who can resolve his own problem... you are only part of the solution through your advises and support...
BRO... here are my suggestions...
look for a priest who specializes in healing (even priests have their own degree of spiritual prowess)... let ur BF always have a session with this type of priests... their prayers and advises are too powerful, dulot sa bukog jud... I know you are trying your best to help your BF, but since its not effective, let those peeps who specializes in such case, handle it this time...
While your BF is still alive, he still have a chance to change his ways... We will just pray for him...
God bless us all!