Hi Cindy.... Most times these are coins that took a hit in circulation. Sometimes these can be explained with a die that was maybe overpolished or possible grease clogging that particular area of the die...... Thing is, it is all a guess unless you can post a photo.
First, welcome to the neighborhood, Cindy! Second, it would be most helpful for you to post a clear, close-up photo of the anomaly since none of us have crystal balls. Offhand, I'm guessing that what you have is simply a "G" that has been damaged in circulation. If you have an understanding of the minting process, you should know that it is impossible for just one coin to be struck with this incorrect spelling, and there were more than 5.6 billion of the 1985 P struck for circulation. Chris
sometimes the circulated coin takes a hit from normal use and disfigures a letter or number making it look like a error.
Usually they do not sell for a premium, but I defintally people pay a few cents for them b/c they are cool.
Welcome to CT. Photos are needed to be sure but the coin is either damaged or struck with a greased filled Die. Either way it's only worth one cent.