Checking that the electrical equipment is safe is not enough. You must also check that the power supply is safe as well. The help of a professional is needed here. The professional must test the power supply on a regular basis to confirm that it is safe enough to be used for electrical equipment. You must never connect electrical equipment to the power supply if it is damaged. Wait until it has been properly repaired by professional people. Testing can also be done on the sockets of the electric power, but be careful that you use the most appropriate tester.