2005 jeep wrangler when i turn lights on beeping starts

Did you RTM read the operators guide yet,
it tells you why all beeps beep and what lamps flash, (warning) and why. did you?
you turn on, the head lights, (what about 1st click , parking lights"?)
and does the dash cluster, show warnings of any kind?

if a door is ajar the system will think, you are exiting veh. with lights on and tell you, buy beeping ,etc.
but on my jeep it says on the dash DOOR, or on EVICs, (not yours)
the newer car even tells what door IS AJAR.
mine on shows , "DOOR"
the operator guide will say, check all doors for ajar, and get warning clear before driving....etc.

if you lost the guide here it is for free

http://justgivemethedamnmanual.com/jeep/jeep-wrangler-owners-manuals/

click the 05 link
ignore beeps, there are just too many .. i look at the cluster and learn to read it..
my newer jeep 08 can produce 1000s of errors,,,,, possible.
in fact the intent it to beep to tell the driver to look at the cluster
for in depth, causes.
see chapter starting on page 136'

once sound it makes is Check gauges chime. so check them.
and headlamps left on
and door ajar.

page 63
NOTE: If the driver's door is left open, and the headlights
or parking lights are left on, the "High Beam
Indicator Light" will flash and a chime will sound.
Lights-On Reminder
If the headlights or parking lights are on after the ignition
is turned off, a chime will sound when the driver's door

its a crude system, and evolved to complex in 2007.
"DOOR" or RF-door , on mine.
or

NOTE: A tone will chime if the turn signals are left on
for more than 1 mile (2 km).

search manual for
"chime will sound"