Megosztott hang

I moved into a new apartment last year. Quiet place, decent rent, nothing special. After about a week, my neighbor from downstairs started acting weird around me. Every time we passed each other, he would stare like I owed him money. One day he stopped me in the hallway and said: “Are you using my Wi-Fi?” I laughed because I thought he was joking. I told him I had my own internet. He didn’t laugh. He just stared and said, “Don’t lie to me.” I showed him my router through the open door of