At work theres this man i dont know to well, just from around the building, sometimes he comes to the part i work in and always comes up to me and says things like 'youre working hard' and things similar then rubs my back or squeezss my shoulder. No other male does it in there. I dont know if he does it with other women as dont pay attention but it throws me a bit. Is this normal in places of work that people you dont know just randomly touch you that way?