Like many others, I always unplug any appliance that is not being used.
Back in 1990, my Philips tumble drier caught fire causing severe damage to the kitchen and smoke damage to the rest of the house.
Luckily I was in the workshop in the garden at the time, the sound of breaking glass alerted me and I was able to put out the fire before the fire brigade arrived.
The failure of a thermostatic switch caused the thing to overheat, setting fire to the plastic drum.
My home insurance paid out £21,000 to repair the damage
I now am very paranoid about leaving anything plugged in, my present tumble dryer is in an outhouse fitted with a smoke alarm.
I never leave the house while using either the washing machine or dryer.
The only things left on are those that need constant power, such as the broadband router, electric clocks and HDD recorder.
Mark