Police are investigating the death of a southwestern Illinois man whose body was found on his living room floor, while his housemate was relaxing on a nearby couch.  Mascoutah Police Chief Bruce Fleshren says the victim found Monday night by officers had been dead for at least a day.  Police arrived at the home after the man’s relatives asked them to check on his well-being.  Fleshren says the man hadn’t been seen since last Thursday and was found with “significant trauma” to his body.  There’s no immediate word on any charges.  The victim’s name hasn’t been released.  An autopsy was planned for yesterday.