AC line measures 27V

replace light switch

It is possible that you have a bad neutral or bad connection aside from a bad light switch. Measure voltage from each conductor to ground with your high impedance voltmeter. They should be close to 120 and 0 respectively. That should indicated which side has a poor connection.

Bill

-- Fermez le Bush

Thanks for the info.

i once ran into a case where oxidized fuses dropped that much voltage. burnishing the contacts and fuses cured the problem (and burnt the chili simmering on the electric stove in another building)

Could also be a phantom voltage caused by capacitive currents between wires. For example, capacitance between a hot and switch-leg run to an open switch can produce a small current that will result in a voltage reading on a high resistance digital meter measuring switch-leg to neutral. There would have to be no load (light bulb) on the circuit. Measuring the voltage with a low resistance meter or attaching a light bulb across the meter leads will make the voltage disappear.

bud--

Replaced the switch. All is well. Thanks to all.

you are welcome.

Now that you mention it, a good test would have been to put the voltmeter across the switch when it was in the on (and off) position. That is also a good way to check for open fuses.

Bill

-- Fermez le Bush