Looking for a contract, or form for the client to sign when dropping off wedding cake.

I never thought about it, but it's good idea.

I made my own. It basically says "by signing below, you acknowledge that the cake was delivered on time and you accept the presentation as is. <company name>is not liable for anydamage to the cake, including total collapse, which may occur as result of the actions of anyone present, be they any member of the bridal party, immediate family, relatives, guests (both adults and children), the photographer, the videographer, any performers (live or DJ), wait staff, and any and all other persons, who disturb or damage the cake by any means including, but not limited to: poking, touching, bumping the cake or the table/display stand/surface on which the cake is displayed, causing vibrations, exposing the cake to heat sources, exposing the cake to the sun and/or wind, and/or moving the cake to a different location or display area, cake spoilage or icing melting off the cake that may occur as a result of high temperatures, weather conditions, failure of the Client to provide a temperature-controlled environment at the appointed location, and/or failure to properly store and display the cake."

But, they usually initial next to this section in the contract, so it's all been said before and they know it (if they were paying attention).