Some debt collectors, and even credit card companies, will try to bully you into making a payment by threatening to garnish your wages. Can they actually follow through on that threat? Yes, but not until they sue you, win, and have a judge decide to garnish your wages as the method of payment. (It's illegal for debt collectors to threaten you with a lawsuit if they don't intend to do so or if they can't legally do it.)
If you are served with legal documents about a lawsuit, it's in your best interests to contact an attorney. Don't ignore the lawsuit; that will only hurt you †When you don't show up to court, the plaintiff (whoever filed the lawsuit) can have a default judgment entered in his favor. This means you automatically owe whatever the creditor sued you for and the court decides how to get the money from you, e.g. wage garnishment.
If you receive notice from your employer about your wages being garnished, but were never served with lawsuit papers, you should definitely see a lawyer. Chances are, the creditor/debt collector didn't do something right and you may be able to get the judgment overturned.
You can avoid a lawsuit and garnished wages altogether by paying off debts before they become seriously delinquent. Creditors can sue you whether you owe them $500 or $50,000. When a creditor sues you and wins, a judgment is entered on your credit report and stays for seven years from the date of filing. For more infomation about wage garnishment read: How Wage Garnishment Is Used to Collect a Debt
Wage Garnishment FAQs