Okay so I was having the same problem and the puddles were all over and I didn't realise what it was until I started at the most common spot for them to appear for a while. Bonelda, the skeleton maid that comes with the supernatural expansion, when she doesn't have anything to clean and if you have a bar she will make drinks and continuously drink them. Because she has no insides when she drinks one it goes through her and makes a puddle. This solves itself as she will clean It up. If you have this expansion and have the bonelda, follow her around for a bit and you will see that the puddles appear after she drinks.