A shock or tingling when touching the washer means you should stop using it and avoid any further contact. Do not test it again with your hand or dismiss it as static electricity.
Isolate it from a safe position
Keep other people and animals away. If there is moisture, do not step into the puddle or reach for the plug behind the appliance. Cut power from a dry, safe point if you can do so; otherwise, ask for help to isolate the installation.
If someone has received a shock, seek medical advice; if there is loss of consciousness, burns, breathing difficulty, or other serious symptoms, contact emergency services. Do not touch a person who is still in contact with a live source, as indicated by the St John Ambulance first aid guide.
What the professional should investigate
They should check the appliance insulation, protective conductor, connection, and operation of the applicable protection devices. The fact that a breaker has not tripped does not guarantee there is no risk. Nor does a socket that looks correct prove an effective protective connection.
Explain where the contact occurred, whether the floor was wet, what cycle the washer was running, and whether there was a protective device trip. Report any leak you observed without trying to reproduce it.
Do not improvise a ground
Connecting the casing to a pipe, reversing the plug, or using shoes as a way to keep washing is not a repair. The installation must be inspected with professional instruments and procedures.
Keep the appliance out of service until the cause has been identified and corrected; the tingling stopping does not confirm it is safe.