brake lights not working only

Somebody help me please! My F-150 Truck brake lights are not working I have checked fuses what else can I check before I have to spend all kinds of money? By the way It's a 1999 4.0 litre. thankyou.

Check your brake light switch mounted on the brake pedal arm under the dash. Check for broken or loose wires, and you can bypass the switch to see if the switch is bad also.