Do white moths mean the spirits are around?

IN some legends, yes. But I've also herd if one come's out of your mouth while sleeping, it means death is around the corner. It can also mean the soul of a loved one is visiting you (example, your dog or your mommy just passed away and there spirits are visiting you).

Here's something nice to read about, however there are thousands of theories on the symbolism. this one is very good: http://www.symbolic-meanings.com/2008/04/09/symbolic-meaning-of-the-moth/