As told by Autumn Murphy...
A man and woman went to Las Vegas for their honeymoon, and checked into a suite at a hotel. When they got to their room they both detected a bad odor. The husband called down to the front desk and asked to speak to the manager. He explained that the room smelled very bad and they would like another suite. The manager apologized and told the man that they were all booked because of a convention. He offered to send them to a restaurant of their choice for lunch compliments of the hotel and said he was going to send a maid up to their room to clean and to try and get rid of the odor.
After a nice lunch the couple went back to their room. When they walked in they could both still smell the same odor. Again the husband called the front desk and told the manager that the room still smelled really bad. The manager told the man that they would try and find a suite at another hotel. He called every hotel on the strip, but every hotel was sold out because of the convention. The manager told the couple that they couldn't find them a room anywhere, but they would try and clean the room again. The couple wanted to see the sights and do a little gambling anyway, so they said they would give them two hours to clean and then they would be back.
When the couple had left, the manager and all of housekeeping went to the room to try and find what was making the room smell so bad. They searched the entire room and found nothing, so the maids changed the sheets, changed the towels, took down the curtains and put new ones up, cleaned the carpet and cleaned the suite again using the strongest cleaning products they had. The couple came back two hours later to find the room still had a bad odor. The husband was so angry at this point, he decided to find whatever this smell was himself. So he started tearing the entire suite apart himself.
As he pulled the top mattress off the box spring he found a dead body of a woman stuffed into the boxspring.
Worst part of this story is that it's true! Check out this link to read about the real life tales that inspired this gruesome legend.