Can't you use wrench events?
i dont know how...
For the light simply use:
(For the switch). Desc = (NONE). Trigger, Click, (Group desc =) Light 1.
(For the light). Desc = Light 1. Wait for, Triggered. Light, player light. Wait for, triggered, loop last.
(For the light with sounds).Desc = Light 1. Wait for, Triggered. Sound, Other, Light on. Light, player light. Wait for, triggered, loop last. Sound, other, Light off.
For the shower use:
(For the switch). Desc = (NONE). Trigger, Click, (Group desc =) Shower 1.
(For the shower head). Desc= Shower 1. Wait for, triggered. Particle, Water A. Wait for, Triggered, Loop last.
For the events mod (Just in case)
http://www.blockland.us/smf/index.php?topic=26603.0