Please know the entrance to residential feng shui. The gap between the two floors of the neighbor faces the living room. Who can help me see how to solve this evil spirit?

The narrow corridor formed by neighbor A and neighbor B is a wind knife, just like a long knife cut at the door of the main house and living room. Fortunately, it is covered by the courtyard wall, which makes it a little evil. It is best to hang a convex eight diagrams mirror outside the living room door, or you can put a gourd on the altar of the living room.