We were able to swing a LOT of pre-existing wiring under that 'cover' & it saved us a lot of time & $$$$.We always go with LED's as I have seen a lot of cooked wires in junction boxes from years of excessive wattage incandescent ceiling lights.

A couple of days ago I bought some "soft white" LED bulbs from ACE and they were ~ $6 each; then later i went to home Depot and saw "soft white" LED bulbs (equivalent to 40W and 60W incandescent) for under $2 - bought those and am going to return to ACE the $6 bulbs ...At $2 a bulb, the LED bulbs start to make more sense in rentals  IMO :)

I was referring to incandescent bulbs.

Motivation for this move is:1) Longevity - the fixtures we are using are rated for an 22-25 year life;2) Cost reduction - the bedroom fixture we use replaces 2 60w incandescent bulbs (120watts) and consumes  ~15watts3) Theft reduction - Students never buy light bulbs ... at least not until they have gone through every bulb in the house ... they just pull bulbs from other fixtures to replace the where the "need" a light.

Maybe a lamp with a low watt incandescent bulb would be enough to keep the pipes warm? 

@Shane CrockettFor improving NOI, focus on reducing operating costs or increasing revenue without added operating costs.As an example, you could reduce electric usage by changing all common area lighting from incandescent to LED.To increase revenue, we added some onsite storage units to rent to the tenants.

Replace with an incandescent bulb or anything but LED.

If you're using incandescent lights(or even the swirly compact fluorescent lights,) you'll save a bunch of money and labor by switching to LED bulbs.

It worked OK for controlling an incandescent floodlight, and later a compact fluorescent floodlight.In my application, I could mount it on the same cover as the lamp socket; it was one of those cast aluminum outdoor covers with 3 holes in it. 

LED Lighting (fixtures)So incandescent is out, CFL’s lasted about two years and now we have LED bulbs but even better...