To sleep Raw On The Floor - is to rest on the ground, normally indoors on someones bedroom carpet, without any comfort aids or sleeping apparatus (ie: pillow, blanket, sleeping bag..)
Derived from the time when you slept round a friends house, but forgot to pack your sleeping bad. Or go to a houseparty - become so intoxicated and pass out asleep on the kitchen floor (usually curled up in the fetal position)
Paul: Where are you sleeping tonight Richard?
Richard: Probably raw on the floor