Reference for Ketubot 205:30

ההוא בי שמשא אתאי שבבתא קא קריה אבבא אמרה אמתיה שתיקו דרבי יתיב כיון דשמע שוב לא אתא שלא להוציא לעז על צדיקים הראשונים:

He used to come home at twilight every Shabbat eve [even after his death]. On a certain Shabbat eve a neighbor came calling at his door. His handmaiden said, “Be quiet for Rabbi is sitting there.” As soon as he heard this he did not come anymore, in order not to cast aspersion on earlier righteous ones.

Jastrow