second home; home away from home
Used for a place where one feels as comfortable and at ease as at one's own home, such as a favorite café, a friend's house, or a regular hangout.
This café is like a second home to me.
He comes over so often that our place is like a second home to him.
我が家 means 'one's own home'; 第二の我が家 extends this to a place that feels like a second home.
Standard kanji spelling; 我が家 is the usual way to write わがや.
Mixed kana-kanji spelling; less common but still seen.
Phrase composed of 第二 (second) + の (possessive particle) + 我が家 (one's own home). The expression is a direct conceptual parallel to English 'second home'.