The Unofficial P64 Resource Forum

Way back in March I after I discovered the P-64 I bought a P-64 from Gander Mountain. The Sales Man noticed the safety would barely move, so he was going to go and get me another one. I had not done much research and did not know that almost no parts were available. So I told I would take it as is. Now to my delight after many months of searching the interweb, I found a guy on Gunbroker who has some for sale @ $40.00 and $45.00 "Buy It Now" He has plenty of other spare parts too. Just key word P-64 to find the auctions.

Your safety or hammer drop switch needed to be disassembled, cleaned and lightly greased. Elsewhere on this forum is a link describing how it's done.

My guess is you probably do not need a replacement.
As mentioned, you need to disassemble it, remove all the cosmoline (read Norm Sutton's excellent posts), and lube it.
Mine was identical until I read up on it and followed the suggestions.

wyo-man