2004 Chevy Silverado gauges not working properly

For some reason the gauges will work when they want. The gauges including battery, gas, mileage and etc will all start going crazy. They will move up & down also other lights will all of sudden come on such as the seat belt, engine light and etc. Usually the seatbelt and other will flicker on & off. The gauges does this on & off while driving down the road. You can be driving down the road and all gauges will all of a sudden move up & down then will reset & work. Then of course repeat the process.

Any info. Would be greatly helpful and thank you for reading my post.