Whereabouts are you seeing these random characters? Although I haven't sold on eBay for a while now if they're appearing when you try to print off an address label then log into your e-mail account and check out the buyer's address as provided on the PayPal notification of payment e-mail. If the address is legible on the e-mail that PayPal sent you then post the item to the buyer, and if the problem is occurring when you try to print address labels via eBay then just address the item by hand using the details in the PayPal e-mail and buy the postage labels from the Post Office instead. If, however, the random characters are appearing on the PayPal notification of payment e-mail then cancel the sale and refund the buyer's money in full via eBay, citing "Problem With Buyer's Address" as the reason why.
