In October, the mother of all emergency alerts will occur in the U.S., but don't be alarmed, it's only a test. We're giving you a heads up, because it the test will be broadcast nationwide to your cell phone, TV, and radio. Here's what to know so you don't freak out and head to an underground bunker when it happens. Where are these tests coming from and when? The Federal Emergency Management Agency (FEMA) and the Federal Communications Commission (FCC) are planning a massive test of their Emergency Alert System (EAS) and Wireless Emergency Alerts (WEA) at approximately 2:20 p.m....