So she called a repair man.
The repairman comes and sees that indeed, the door falls open every time when a bus passes by.
"OK, I am gonna see what is going on, just close the door behind me" and he steps into the wardrobe.
At that time the husband comes from work, opens the wardrobe and finds the repairman.
Husband: "What the hell are you doing here!"
Repairman:
Spoiler:
