You might want to consider investigating the quality of the ground at the outlet the washing machine is connected to... grounding has been through some SILLY iterations over decades... like using copper water pipes or sheet-metal forced-air heating/cooling ducts as grounds. And even if there is a copper grounding rod buried 10 feet in the ground, if it is very old (more than 30 years old), it can be mostly dissolved. The proper fix would be to have a new ground rod installed and a new grounding bond established. The only problem with testing a ground is that you need a known-good ground for a reference. Another possible trouble point can be any wire splices between your washing machine outlet and the fuse box/circuit breaker box. If those wire splices are "friction" splices with crimped connections or wire nuts, remove whatever is holding the wires together, solder the correct wires together and insulate the solder joints carefully. Over time, this type of electrical connection can become oxidized or the screw-thread pressure holding the spliced wires together can become loose or oxidized (or both). I would also recommend checking the washing machine outlet... if the electrical wires are held on with screw terminals, make sure all of them are tight... heating and cooling from 1000s of washing machine cycles over decades can cause friction connections like screw terminals to loosen. You can then also have the fuse-box/circuit breaker panel examined to be certain all of those screw-down terminals are all still tight and "fresh" (so they conduct easily). Finally, there is probably a main circuit breaker on or in your home that is separate from the fuse box/circuit breaker panel. Find it. Disable power supplied to it, then make sure the screws on the terminals in that main circuit breaker are all tight. Our 1969 home (USA) had the electrical ground connected to the copper pipe that connected the house to the fresh water service under the street. In 2014, we dug up that copper water line to examine it for corrosion... the copper was so thin, it was super-easy to bend the copper with a finger or two. Pin-holes were developing in the pipe. This was bare copper pipe buried 43 years earlier and it probably should have been replaced 5 or 10 years ago. The replacement pipe was coated with plastic to prevent corrosion with dirt and moisture to stop the corrosion more permanently. I once had an electrical problem caused by the wire in the walls of the house coming into contact with ONE stray nail inside the wall. Over decades, the nail pierced the insulation and made a high-resistance path to ground on the "hot" side of the wiring to a bathroom. It produced odd problems until the nail was found and the wire was protected.