Why do all turn signals turn on as if hazards were turned on when you use right or left signal and lights inside car also flash?

When all turn signals activate simultaneously, it usually indicates a malfunction in the vehicle's turn signal system, often caused by a faulty turn signal relay or a wiring issue. This can happen if there's a short circuit or a problem with the switch that controls the turn signals. Additionally, the interior lights flashing along with the turn signals is typically a symptom of the same electrical issue, as they may be incorrectly wired to the same circuit. It's advisable to have a professional mechanic inspect the system to diagnose and resolve the issue.