Puppies love to chew. Electric wires can mean instant death to puppies. If you are not using it unplug it or put it up out of puppies reach. Furnish chew toys or a hard rubber ball for the puppy to play with. Be sure the toys are made for dogs.
Garbage cans are another potential source of danger.
Most puppies like to root through the contents. Make sure the lids are on tight. Some puppies are capable of opening cabinet doors, especially those that are ajar. If you keep bleach, detergent or poisons in these cabinets either move them or put a childproof lock on the cabinet. Keep toilet lids closed, or better yet, keep your bathroom door closed.