electrical
I am replacing a dimmer switch with a regular switch. The dimmer switch controlled a chandelier light that I just replaced with a ceiling fan. There is also another switch that controlled the light, it is not a dimmer, it is a regular type.
Do I need a three way switch, and how do I wire it up?
Many dimmers have an adjustment for the minimum level. You don't mention what type of dimmer you have but you can consult the instructions on how to adjust this. As @dslake mentions in his answer, adjustments might be via a knob or screw, but if it's digital, it could also be a button sequence.
Needing to perform this is more common with electronic dimmer switches since they need to work for many different types of bulbs (incandescent, CFL, LED).
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.
Best Answer
As the others have said, you need a 3-way switch.
The copper colored screw on your old dimmer is your "common" screw. The other two are your travelers.
The new switch will have similarly color schemed screws. Typically black for the "com" and brass for the two travelers.