The chance of getting caught by sophisticated police detection equipment is less than 0.001%
The chance YOU will screw up and do something dumb to bring law enforcement attention is 4.999% - Getting high while you are driving with 5 pounds of weed in the front seat, etc. punching your gf in the head and having the cops come to investigative and they find your grow, etc, etc, etc.
The chance that "everyone in your house" will tell just one person and that person will tell one person and before long the whole neighborhood knows including the cops is about 95%. If you can't even keep a secret why would they?
So the chances of getting caught really depend on you. That is why people can't tell you if you will be caught or not.