I’m Czech. A part of Silesia is a part of my country.
Since Ostrava (a main city of a Czech part of Silesia) is a mining city, we usually see Silesians as miners. They pronounce words shorter than others do and it is being said that they use rude words often.
So, a stereotypical Czech Silesian in Czech eyes would be a miner with a specific speech.
In a local sitcom, Bruntál (another town is Silesia) is described as a cruel and dangerous location where only broken bone is considered to be a sickness (having flu, for example, is just being a pussy).