Testing a fuse with a cellphone - GIF

[mklotz]

But does it work????? seems to me to be a pressure based application... Anybody having a supporting comment???

Phones use capacitance switches which detect the change in capacitance when the capacitance of a human is connected to the switch. (More on that subject here...

https://en.wikipedia.org/wiki/Touch_switch

so the human must be in electrical contact with the switch to operate it. He is if the fuse is good; if the fuse is open he's not in contact.