Four letter words with the same first and last letter are:areaariaaquaaurabarbblabblobbulbchicdeaddeeddieddyedeaseeaveedgeelsefiefganggonggroghashhighhushkickkooklolllullmaimneonnoonnounoleoontoOreoorzoouzopeeppimpploppomppoopprepproppulppumprearroarsanssasssoustacttartteattauttenttesttextthattilttintToottorttouttrottufttwitwhew
kayak and level
empty
illieration
Hugh Hefner
Four letter words with the same first and last letter are:areaariaaquaaurabarbblabblobbulbchicdeaddeeddieddyedeaseeaveedgeelsefiefganggonggroghashhighhushkickkooklolllullmaimneonnoonnounoleoontoOreoorzoouzopeeppimpploppomppoopprepproppulppumprearroarsanssasssoustacttartteattauttenttesttextthattilttintToottorttouttrottufttwitwhew
kayak and level
Nine letter words that begin and end with the same letter:beachcombdartboarddecimateddecorateddecreaseddefrostedeffectiveeradicateetiquetteexecutivefireproofflagstafffoolproofgatheringgroundhoghairbrushhopscotchhundredthmagnesiummidstreamnarrationnewswomannightgownnutritionrainwaterrecruitersailboatssentencesturbulent
empty
That is a good question, "that" is a good answer.
Here's an example of a five letter word which reads the same when the first and last letters are dropped: gnome and nom (as in 'nom de plume')
Roadrunner
illieration
empty
toot
The word is empty. If you take away the first, last and middle letter the word sounds like mpty, empt and emty.
hears, ear