Wire short circuit

I can’t determine which wire is broken. Phase (1) goes to the double switch and two wires go out to illuminate the kitchen (2) and the toilet (3). 1 + 2 = the light is on in the kitchen. 1 + 3 = light is dimly lit in both the toilet and the kitchen. 1 + 2 + 3 = in the kitchen the light is on in the toilet is not. Between 1 and 3 when the lamp is turned off, the voltmeter shows 0 Volts, between 1 and 2 when the lamp is turned off, the voltmeter shows 220 Volts. If I feed the phase from the socket to 3, the lamp lights up normally, if I feed the phase from the socket to 2, a short circuit occurs.