A recessed light, sometimes called a can light, has both its housing and bulb recessed above the ceiling drywall. Converting a standard ceiling light fixture to a recessed light involves removing the old fixture and its electrical box and installing the new recessed light, usually in the same place. Alternatively, you can install the new light in a different location nearby. This is a simple project as long as the existing circuit cable can reach the light; if not, you have to install a junction box and extend new cable to the new light location.
Be sure to use an IC-rated light, which is safe to be in contact with ceiling insulation. With fixtures that are not IC-rated, you must keep the insulation several inches away from the fixture housing to prevent a fire hazard. Leaving the housing and surrounding area without insulation creates a big thermal hole in your ceiling that lets heated air escape into the attic.
Tip
If you don’t have access to an attic above the ceiling, use a “remodel” light fixture that can be installed from below the ceiling.
Before You Begin
Turn off the power to the ceiling light fixture first by turning off the light switch, then flipping off the appropriate circuit breaker in your home’s breaker box. You cannot turn off the light switch only; this is dangerous. You must turn off the circuit breaker.
Turn the light on and off at the switch to confirm that it is not powered. If the light doesn’t come on, you can proceed with the steps below.
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Source: The Spruce