My best guess, Security alarm door switch, tells BCM if door Are locked/unlocked and arm/dearm alarm and activate/deactivates interior light.
Its located inside the door, back side of handle, at the back of the key cylinder, its attached there with a C clip, also check wireing harness for broken wire all the Way thrue door boot.
Messuring parameters and part number, see my thread "interior light problem"
2004 Grand Cherokee Overland 4.7 HO Quadradrive
95 ZJ Limited 5.2 Winter Project
Sold 94 ZJ Laredo 4.0 Winter Beater
R.I.P. 2000 Grand Cherokee Limited, 4.7 V8, Quadradrive, Shale Green Metallic, Agate/Carbon interior, Well modded and highly missed :(
MONEY WILL CONTINUE TO BE THROWN INTO THE RIG UNTIL CONDITION AND SATISFACTION IMPROVES!!!