As always google is your friend (and the first place to start when looking for Fritzing parts). A search for “fritzing part ACS712” turns up a variety of options. I’d use this one (his parts are generally decent):
http://omnigatherum.ca/wp/?p=338
the web page is a bit weird, you need to right click on the text and select “save link as” to download the .fzpz file for the part (file->open in fritzing will load it.)
Peter