The etiquette for wearing a ball cap backwards when entering someone's home after church, or any formal setting, is generally considered informal and somewhat impolite. Wearing a ball cap backwards is typically seen as a casual and relaxed style, which may not be appropriate for certain social situations, such as after attending a church service.
When entering someone's home after church or any formal event, it's advisable to remove your cap or hat entirely as a sign of respect and courtesy. This gesture shows that you acknowledge the more formal setting and the presence of others. By taking off your hat, you demonstrate good manners and cultural sensitivity.
Of course, specific etiquette norms can vary based on cultural or regional differences. In some more relaxed social settings, wearing a ball cap backwards might not be an issue. However, when in doubt, it's best to err on the side of formality and remove your cap upon entering someone's home after a church service or any other formal occasion.