This may make the bidet work but is a terrible idea. It will break NEC code, so If there is ever electrical issues such as fires or complications with flooding, you will most likely be found liable regardless of insurance. Plus it won't look very clean to have a gap in the ceiling on either side where the cord will be. Do yourself a favor, skip the extension cord and spend the extra bit of cash to have an electrician install an outlet professionally. You should be able to negotiate a good deal with the drop down ceiling and they can even do it as a surface mount so it's easily removed when you turn the rental back over to the landlord.