Punctuation use with quotation marks

When you insert a word inside quotes, and the word is followed by a punctuation mark, is the punctuation mark placed inside the quotes or outside? I'm not referring quoted speech as in a book (Example: "Oh!" she exclaimed) but in a regular sentence.

specific example:

I'll be going to the Harry Potter Faire dressed as a "Muggle," since I don't have any costume.

VS

I'l be going to the Harry Potter Faire dressed as a "Muggle", since I don't have a costume.