A The wiring of three-way switches is certainly more complicated than that of the more common
single-pole switch, but you can figure it out if you follow our diagrams.
If it works alone, it's a simple, single-pole switch. If you can operate the light from two locations, the switch (or switches, if you replace both of them) you'll need is a three-way switch.
Now that your brain and your tool belt are overflowing, let's start with the replacement of a single-pole switch. Make sure your circuit is dead, then remove the coverplate and switch retaining screws.
Single-pole switch configurations with up to 12 throws are available, as well as SPDT and DPDT versions.
Simple, so-called
single-pole switches might have only three wires--two insulated wires that carry current and a ground wire, which is sometimes not insulated.
Although
single-pole switches might have been included in the instrument to open the circuits of three of the dry cells when the comparator is not in use, this was considered an unnecessary refinement.