What did we say? You need to talk to whoever first, explain you dont like being touched.
If the touching is sexual or continues “constantly” yes, you should go to HR.
But dont take “Hey, Dave, the guy who shares my cubicle? He touched me on the shoulder to ask me a question. It only happened once, but he should be fired right now. Unwanted touching!!!”
It’s the difference between:" I saw my manager stealing from the petty cash" vs “My manager made a* personal phone call*- on company time!”