How did they had tatoo machine in 1931(I think), actually, did they had electrical power in that asylum which is so dislocated from civilisation in that time??
shareThe electric tattoo machine has been around since 1891.
As for electrical power, very possible. You see there's a large lake/river at the foot of the village in some of the scenes, and hydroelectricity was very big in Spain. As far back as 1919, in Catalonia alone 100,000 workers at a single hydroelectric plant went on strike! So yes, it's very very plausible that the asylum had electricity. Almost definitely, I would have said.
Spain was a very modern and well-organised country, until Franco's forces plummeted it back into the dark ages.