Moving the motion sensor on a motion sensor light...?

20 feet should not be a problem. You probably need to adjust the sensitivity lower. Check your manual on how to do that.

Bert

There are also motion sensor switch kits with attached low voltage control cable that can be wired in remote to the controlled light fixture; you may want to look into using one of these.

Most of the combination sensor/flood light products on the market have only 120V connections leaving the control housing. If you were to cut the connections to relocate the control head, you would need to run 120v 3-conductor wiring to the new location and observe appropriate installation rules for 120v circuits; but for all that trouble, you could just install a new 120V lighting location instead.

Motion sensor lights typically use infrared detection. However, they operate by detecting sudden changes in infrared radiation within their field of view. A stationary source of infrared radiation will not set off the detector. The source has to be in motion. If you simply move around periodically while in the corridor, the sensor will detect the motion and keep the light on.

What Bert C says is correct, 20 ft. should not be a problem. I just adjusted the sensitivity down on ours to encompass a longer distance(sidewalk to back door), which is about 25 ft. You need to check the manual to do it though.

If you follow all electric code requirements yes.

You could.