Yes it could be the General Electronic Module. This diagnosis would require
the Ford scan tool, STAR tester or WDS, to pinpoint the body code (B-series)
and to try to reset it first before replacing it.. There is also programming
involved. The Ford antitheft system software is sometimes, on some models,
split up among different modules, Instrument Cluster Module, GEM, PCM and
others. It gets complicated if you don't have Ford OEM information
procedures and the scan tool.
Chino Autotech Inc.
The GEM module controls the interior lights you describe, but the alarm
and keyless entry functions are controlled by the central security
module. The GEM is located behind the glove box, and the security module
behind a trim panel on the right side of the cargo area. The two
modules work together, so further diagnosis might be necessary to
determine exactly where the fault may be. You may also want to check out
the ignition switch, as the GEM relies partly on input regarding the
position of the ignition switch for proper operation...
JS Auto Supply
Yes. It's a common problem among most Fords. It is under the dash.