Power LEDs from wall outlet without transformer plug?
Make your own from an LT3799



The transformer is 21mm x 21mm x 17mm approximately and I think this will be the largest part in the circuit. The MOSFET will probably be an FDPF15N65 and this is a TO220. If you still have room it's probably best to build it using the circuit in the data sheet on page 16 - they have EMC components on the power side.