What age is it safe for a child to have a electric lighted doll house?

My Grand daughter will have a electric doll house with 12 volts of electricity. I wonder how safe this is for a child of age 3?|||I have a four year that loves things that plugged in but I have to watch him. Maybe test it to see how she does. I would watch her close at first. If the cord is removable maybe take it out for about six months and then try it again.|||If you're granddaughter is normal, then 4 or 5. If she is a drooling retard, then never.|||Sorry, I think she is to young, that could lead to her being hurt. Save it until she is older. Better safe than sorry :) Hope I helped.|||IT DEPENDS ON THE VOLTAGE OF THE LIGHTS USED. I BUILT FOR A FRIENDS DAUGHTER A HOUSE THAT USED A 9 VOLT TRANSISTOR BATTERY SYSTEM. THE BATTERIES ARE USUALLY HIDDEN OR LOCKED AWAY WHERE CHILD CAN'T GET TO....9 VOLTS IS VERY WEAK ANYWAY