Have you ever replaced a light switch?
 

My switch just popped out and Lowes says I have to replace the entire switch and buy a voltage regulator to be sure the power is off.

Other than that, any helpful hints? I would hate to get zapped today.

Check You Tube. Call an electrician.

Call an electrician. Seriously.

Make sure the breaker is off in the room you are replacing the switch in. It's easy to replace I have done it several times.
Or round up a handyman relative or friend to do it.

No one is available today and they say the main thing is to be sure the power is off and the rest is mechanical. I've watched before but this will be my first time trying.

Do you mean the toggle switch? Turn off the breaker in the breaker box that supplies the power to that switch. Change it out, usually three wires that have wire clasps attached with screws. A youtube video will guide you through. Should take you about 10 min. Replacing a switch or plug doesn't require a license but wiring it does.

Yes, the toggle switch. I went to turn off the light and it came right off, never knew that could even happen. I wouldn't attempt to wire anything.

I have one of those devices that test for electricity is still on. Very handy to have in your tool box.

I think you mean a voltage meter rather than a voltage regulator. They are useful things to have around. If you turn off all your power and see that the electrical meter is not running, you won't need to test voltage to the switch. Otherwise you need to be really sure that you turn off the right breaker. The labels on the breakers in the electrical panel may not be complete or correct, so don't rely on them to tell you which breaker serves the faulty light switch.

I just did a whole house of plugs and switches. I use rubber handled screw driver and pliers to prevent my getting shocked. As you take one wire off the old switch attach it on the new switch in the same place on the new one -do each wire the same way. This will assure you they are in the right place then put it back in to the wall/box-attach the face plate. easy peezy