On top thats is usually powered by the elevator and thus the elevator's installors responsibility, the shaft lights might be your responsibility,
But your State Code may vary.
Ususally in this State the light above also includes the cab lights(same circuit/service) is a single fused disconnect (lockable) thats in the elevator room, sent over to the elevator control unit.
But your State Code may vary.
Here's Texas's
http://www.license.state.tx.us/elevator/elerules.htm
I didn't read anything about the above listing, I found this on a commercial web site
Here
This commerical site has a complete listing (seems up to date-per calendar year) of various construction codes, with hot links right on the page (kinda cool).
Using a search engine and the terms -
texas elevator codes found these listing, all of the above are the same as previous stated and linked from the web search.