There are a few easy steps you can take ensuring the safety of your home from improperly wired outlets and loose outlets.. first, purchase an inexpensive 3 prong outlet analyzer (checker), and check every single outlet you can.. outlets wired improperly will show on the chart included on the tool by the light placements and which lights illuminate and in what order. If it says you have either a reversed polarity (wires installed hot/neutral reversed) or an open ground (ungrounded outlet) then you have a potential for electrocution. Outlets without grounds are every bit as dangerous and either situation needs immediate correction by a qualified Electrician. There is a rather rare occurrence of what is called a Bootleg Ground and a Reversed Bootleg.. these can only be checked by opening the outlet, having expensive testers or purchasing a Non-Contact Voltage Tester and place the tester near the face of the outlet near the ground hole, if mis-wired it will signal without even inserting the tester. These Bootleg wiring methods are very dangerous! The following link explains them in laymen terms and shows how to test for them.
Homes equipped with two prong outlets require purchasing a two wire tester and inserting the pins one into the small hole and one touching the screw holding the cover on the outlet, if it is wired properly and grounded this should light the tester.. if not stick the pin into the larger slot and once again touch the screw holding the cover on the outlet and if it lights up then you know you have a reversed polarity outlet. If the outlet is not grounded the light will not illuminate when these tests are performed. One other potential hazard rarely seen but possible is 2 hots to the outlet making the tester light whether it is on the small or larger slot and the outlet cover screw is touched.
Another easy item to check for is cheap outlet cover made in China that are easily pulled away from the wall and small children could be harmed if they insert kitchen utensils or tools they find around the home.. so be safe, be sure, be pro-active!