electrical
The switch in this adaptor only disconnects one of the live lines. What kind of switch where both are disconnected when you turn it off?
What is the advantage of the latter (or hazard of the former)?
top and bottom view of it. It's 240 volts. 2 live hots.
The multimeter may be off trying to accurately measure an AC voltage that ends up looking like chopped AC cycles.
There is a good possibility though that no load on a triac switch of the dimmer could look like an AC waveform of full voltage to the relatively high impedance of the multimeter input if the dimmer design has a resistor/capacitor snubber circuit across the triac. The diagram below shows the typical snubber configuration used (R2 and C2). R2 is commonly a resistor of a couple hundred ohms in series with the capacitor. When the triac is OFF the snubber circuit will be able to pass the AC waveform through when a meter with an typical input impedance of 20K to 50K ohms is used across the open lamp terminals.
Wire number 1 is your switched power wire from the switch, wire number 2 is the neutral path back towards the panel, and wire number 3 is the neutral wire coming from other outlets down the line.
The reason you read 70 volts on number 3 is that something on that circuit is using power and you disrupted the path. You can be shocked if you complete the circuits. Even if nothing is plugged into the other outlet there is most likely another outlet on that neutral with something plugged in. You see this with a lot of homes with knob-and-tube wiring.
Think of it like this you turn on the faucet and fill a glass of water, you put the rim of the glass halfway in the stream, some water fills the glass the rest is going down the drain. Think of the number 3 wire as the drain and a light bulb for example as the cup. That's why you read 70 volts
Best Answer
Philippines:
You're sunk. You can't do that with this adapter. It's not a Philippines adapter, it's a North America/Japan adapter.
(For our readers, the former USA-developed areas of the Philippines use USA-style split-phase, but for nationalism reasons serve only 240V so neutral does not exist. This makes it compatible with the rest of the country which uses standard Euro 1-of-3-phases of 230V. In USA areas, since both wires are far from ground potential, both must be switched for safety.)
This problem is greatly compounded by the unfortunate policy in the Philippines of using the NEMA 1 and NEMA 5 receptacles for 240V (when there's a perfectly good spec called NEMA 6 specifically for what they are doing, but good luck telling a whole country they're using the wrong socket). So you have polarized NEMA 5 receptacles with the neutral being 120V from earth and the hot being the opposite 120V from earth.
Honestly, you will never find a BS1363 that switches both legs. That is simply not required for that appication (anywhere else but Philippines). I would advise actually installing a proper BS1363 right next to a 2-pole switch, and then superglue and sticker over the on-socket switch, so people use the off-socket switch.
Although honestly, Britain are the only people in the world who put switches on receptacles.
Everywhere else in North America, Colombia and Japan:
Under the UK BS1363 standard, the switch on the socket is required to switch off the hot wire. The neutral wire is (supposed to be) near earth potential, so there's not a lot of hazard to leaving it connected. So there is no need to switch neutral.
Hence one which switches both is unlikely to exist.
North America's voltage is lower, but has the same "hot + neutral + earth" scheme, with neutral also (supposed to be) near earth potential.
It needs to be polarized so the switch is switching the 120V hot wire. On the NEMA 1 and NEMA 5 15A connectors, polarization is done one of two ways:
On 3-prong plugs, they don't bother with the tall neutral.
This thing appears to be 2-prong and with no polarization. It's an incompetently designed Cheese cheapie, and the switch is theater (because 50% of the time it'll be switching the neutral). No testing lab stamp, of course.